Why the hate with endgame fights?

[Kazrah]

It's certainly a balance issue. Although hardcore raiders want more challenging content (and devs indeed wish to provide that), the echoes of Gordian Savage ring through the halls of SE, reminding them of what happens when content is made too difficult to the point where jobs are ruled out on a globally universal level. There's probably a desire to expand the percentage of players competing in savage content, which would lead to more reason for them to make that content easier while providing unending raids to keep the more consistent savage players content.

As for me personally, I don't really do savage mostly because I don't really care. Endgame for me is either extreme primals (usually against my will) or 24-player raids, because the most entertaining combat mechanic for me has always been the difficulty of getting 24 people to communicate.

[Moomba33]

I don't really see more hate towards endgame fights in SB compared to earlier in this game's life. Closest I can think of is the "waste of resources" argument that sprouted up around Ultimate Coil.

The Shinryu nerf requests weren't any more extreme than the complaints that came up around the Steps of Faith. Hashmal complaints aren't really any different than the Weeping City complaints of Heavensward.

Some complaints that existed in ARR don't even have an equivalent now like the story gating in Coil being resolved by normal mode raids in the expansions. Or the difficulty of pre-nerf Pharos Sirius dungeon never coming up for future dungeons since they've all been easy since then.

So part 1 of my answer is: I don't think there was a straw that broke the camel's back as difficulty complaints are nothing new.

As for why this is I'd say it comes down to a lack of difficulty curve in the overall game. After going through 100+ hours steamrolling over content it can come as a system shock when failure has consequences. Some people are motivated by challenges and want to improve and overcome them. Some people are discouraged and would rather go do something else when they hit a wall. Some will complain and hope the challenge level is brought down to a level they deem acceptable. Others simply don't enjoy the challenge presented by this game (strict memorization to avoid instant deaths) and may hope that feedback will lead to different challenges they can enjoy.

Part 2 of my answer is essentially that a sudden bump in difficulty will be handled by different people in different ways depending on whether they find the presented challenge enjoyable or not.