1e & 2e
I can't remember a lot of things that were added being hated when they were added, but I do remember almost universal rejection of 2e's attempts at addition through subtraction. In particular, the initial rules that said Paladin's were just Fighters prompted a lot of hate, and were a big part of why I think the group I was with rejected the game at the time.
I think in general I can describe the groups I was with at the time as loving virtually every new option, even if in retrospect we should have realized that they were bad for the game. The things that 2e added to the game, like expanded NWP, a core class bard, dragons with regular stat blocks, and expanded spell lists were embraced. It's only where it was perceived as taking away things that it wasn't.
3e
I didn't hang out with a lot of people that hated 3e, and consequently I was probably it's biggest critic. And the bulk of my hatred was focused on Prestige Classes. There were individual options I didn't like, but it was only Prestige Classes that I came to hate as a concept.
Level of the spell is added to the DC to resist it. In a universe where the power of the casters already grew exponentially, this to me was the key tipping point that caused their power level to be out of control. There were other problems, but none so critical as the fact that unlike prior editions, as the caster leveled up, they could expect targets of their spells to be less likely rather than more likely to resist the effects.
Pathfinder, 4e, 5e
At will cantrips. I hate them. And while the players like having 'more', I think most of them also agree that they really put constraints on the game (or what can be a cantrip) that aren't fun.