The reason that you get terrible gear in Inferno is because they scaled it up very rapidly from act 1 to act 3. Act 1 was built to be doable in Hell and Act 1 gear. Think like Warlords and Doom Armor, and a level 61 weapon.
The idea was you'd get through Act 1, then continue to farm Act 1 for like a month until you could do Act 2. You'd then get through Act 2, and farm Act 2 for like a few months until you could do Act 3, and finally after a few months get through Act 3 and 4. This process was designed to be "the endgame" and was expected to take players months to complete.
The problem was players within a week started used kiting, exploits, and other tricks to skip into act 3. They then hung out in act 3 and farmed chests when they couldn't kill monsters, or let Tyrael kill things for them, or various other tricks to kill monsters without having the expected amount of gear. This let a bunch of things, especially 1k+ DPS weapons into the economy.
Players in Act 1 etc. were highly discouraged because floor-munching tyrael farmers were flooding the market with cheap 1k+ dps weapons, and level 63 armors, but playing normally meant that you couldn't find any items like that. It quickly became obvious that it was much faster to buy a 1k dps item off the AH than it was to farm up so much gear in Act 1 that your overall armor stats boosted your terrible 500 DPS weapon up to a comparable level.
To combat this problem, Blizzard tried to do a number of things to reduce the influx of items from Act 3 from players who couldn't actually kill monsters, but the damage had already been done. Thousands of 1k dps weapons were already in the wild on the AH. So to try and mitigate the effect, they let all items drop from any act in the game, at least letting players have the opportunity to find upgrades on their own.
This ultimately leads to a very quick trip through acts 1 and 2, because level 63 items are ubiquitous. However, to stop too many level 63 items from flowing into the game (and thus making it what they consider too easy to get through act 3 and 4) they reduced the drop chance of level 63 items from Act 3 and 4 since it is supplemented by Act 1 and 2 farming.
In the end it means that most players now-a-days have access to all the leftover 63 gear that is being farmed up by all the players. Level 63 gear (properly rolled) was designed to allow you to do Act 3 content, and Act 3 content was tuned to be far too hard for someone geared only in Act 1 gear. So obviously someone in Act 3 gear will have a trivial time with an Act 1 monster.
Add to the fact that the butcher is already an easy monster to kill. Add also to that the fact that Life Regen is a stat that is highly variable in it's usefulness. Fighting a monster that deals 2k DPS with 20k health and 2k health per second means you will last forever. Fighting a monster that deals 4k DPS with 20k health and 2k health per second means you will last 10 seconds. Consider that Act 3 monsters deal 8 times or more damage than Act 1 monsters due to the original intention that players would have Hell/Act 1 items in Act 1 and Act 2/3 items in Act 3.
It's not surprising. It doesn't mean the game's too easy, but it means that the availability of Act 3 items in Act 1 can trivialize Act 1 (whether due to AH or due to dropping in Act 1). Items are just another form of progression though. I'm pretty sure Hell Diablo is trivial too, because you outgear him as well. The whole purpose of items is to make you stronger, the result of becoming stronger is that monsters become easier. The fact that the game is built around being a gear check is no secret, the whole game is about getting better items, and that monsters that are too strong before you get better items become easier as you get better items.
Ultimately I think that a much shallower stat curve and a much narrower difference between 61 and 63 gear would have been better for the game's longevity. It would allow more overlap across tiers, and things like level 61 weapons might occasionally be useful, and the entirety of act 1 wouldn't be completely trivial by the time you were able to do act 3.
2.5% lifesteal in Inferno is actually 0.5% lifesteal.
A rare with large health pool has maybe 2 million health. That means over the course of killing a rare with 2 million health, you recovery about 10,000 health regardless of your DPS. I don't think lifesteal will ever become viable because of that.
If you ever get enough DPS to make it worthwhile, monsters will die so fast that it's unnecessary and you'll heal yourself with health globes faster.
2
The idea was you'd get through Act 1, then continue to farm Act 1 for like a month until you could do Act 2. You'd then get through Act 2, and farm Act 2 for like a few months until you could do Act 3, and finally after a few months get through Act 3 and 4. This process was designed to be "the endgame" and was expected to take players months to complete.
The problem was players within a week started used kiting, exploits, and other tricks to skip into act 3. They then hung out in act 3 and farmed chests when they couldn't kill monsters, or let Tyrael kill things for them, or various other tricks to kill monsters without having the expected amount of gear. This let a bunch of things, especially 1k+ DPS weapons into the economy.
Players in Act 1 etc. were highly discouraged because floor-munching tyrael farmers were flooding the market with cheap 1k+ dps weapons, and level 63 armors, but playing normally meant that you couldn't find any items like that. It quickly became obvious that it was much faster to buy a 1k dps item off the AH than it was to farm up so much gear in Act 1 that your overall armor stats boosted your terrible 500 DPS weapon up to a comparable level.
To combat this problem, Blizzard tried to do a number of things to reduce the influx of items from Act 3 from players who couldn't actually kill monsters, but the damage had already been done. Thousands of 1k dps weapons were already in the wild on the AH. So to try and mitigate the effect, they let all items drop from any act in the game, at least letting players have the opportunity to find upgrades on their own.
This ultimately leads to a very quick trip through acts 1 and 2, because level 63 items are ubiquitous. However, to stop too many level 63 items from flowing into the game (and thus making it what they consider too easy to get through act 3 and 4) they reduced the drop chance of level 63 items from Act 3 and 4 since it is supplemented by Act 1 and 2 farming.
In the end it means that most players now-a-days have access to all the leftover 63 gear that is being farmed up by all the players. Level 63 gear (properly rolled) was designed to allow you to do Act 3 content, and Act 3 content was tuned to be far too hard for someone geared only in Act 1 gear. So obviously someone in Act 3 gear will have a trivial time with an Act 1 monster.
Add to the fact that the butcher is already an easy monster to kill. Add also to that the fact that Life Regen is a stat that is highly variable in it's usefulness. Fighting a monster that deals 2k DPS with 20k health and 2k health per second means you will last forever. Fighting a monster that deals 4k DPS with 20k health and 2k health per second means you will last 10 seconds. Consider that Act 3 monsters deal 8 times or more damage than Act 1 monsters due to the original intention that players would have Hell/Act 1 items in Act 1 and Act 2/3 items in Act 3.
It's not surprising. It doesn't mean the game's too easy, but it means that the availability of Act 3 items in Act 1 can trivialize Act 1 (whether due to AH or due to dropping in Act 1). Items are just another form of progression though. I'm pretty sure Hell Diablo is trivial too, because you outgear him as well. The whole purpose of items is to make you stronger, the result of becoming stronger is that monsters become easier. The fact that the game is built around being a gear check is no secret, the whole game is about getting better items, and that monsters that are too strong before you get better items become easier as you get better items.
Ultimately I think that a much shallower stat curve and a much narrower difference between 61 and 63 gear would have been better for the game's longevity. It would allow more overlap across tiers, and things like level 61 weapons might occasionally be useful, and the entirety of act 1 wouldn't be completely trivial by the time you were able to do act 3.
1
2.5% lifesteal in Inferno is actually 0.5% lifesteal.
A rare with large health pool has maybe 2 million health. That means over the course of killing a rare with 2 million health, you recovery about 10,000 health regardless of your DPS. I don't think lifesteal will ever become viable because of that.
If you ever get enough DPS to make it worthwhile, monsters will die so fast that it's unnecessary and you'll heal yourself with health globes faster.