I didn't realize there was such a large outcry against the Samurai changes and I would just like to add my voice to it.
Resource Management
Having two ways of 50% resource spend with Kaiten and the large damage OGCD made it pretty tricky to not overcap on kenki, while always having enough kenki saved for your required spending. With the kaiten removal and kenki cost regulation the resource management is completely gone. You can just hit the buttons when they glow and you probably won't drift anything more than a single GCD, it's so thoughtless. Reducing Senei to 25 kenki sucks, but it's not the biggest deal on its own. However, with the kaiten removal those changes together entirely removed an area of optimization and fun for this class
Tsubame-gaeshi charges
Freestyle samurai is no longer a meme anymore, the difference in performance between a Samurai with 0 knowledge of timing optimization and a Samurai making sure to line everything up is minimal. It wasn't even that large of a gap before, but always lining your cooldowns up was so immensely satisfying to do right, it felt very rewarding. This is not even that large of a reduction to the the skill cap on its own, but with resource management being completely removed the class has nothing to think about. This change really doesn't make sense to me becuase it makes it easier for the casual Samruai to reach the class's max damage output, but casual content doesn't require anywhere near that kind of effort, so why ruin the fun for other players when the aid for casual players is nowhere near needed or even noticable.
Kaiten itself
People have talked about this one so much that I don't have much to add. I'll just quickly say that yeah, the button felt good to press and added to the resource management minigame. Removing this button, especially with their reasonsing of button bloat despite the new skill they just added having it's own bind despite being solely attached to Ikishoten, simply does not make sense. This button adds so much satisfaction and slight nuance to the rotation that removing it could only conceivably be done by someone who only plays the class in AOE.
Difficulty reduction
I understand making the classes easier as this game is primarily focused towards casual players, but I passionately believe every role should have a class that has a more involved rotation, for the players that care. Samurai, as the melee selfish dps, should parallel Black Mage in its rotational room for optimization. Casual melee players have plenty of options for easy rotations, why remove their option for a more involved rotation? Shadowbringers freestyle Samurai could easily pull its own weight and more in any casual content, and the hardcore players still had a ton of room to optimize. Please, bring that back. Attach the new skill to Ikishoten, undo the kenki cost reductions, give us kaiten back, and make Tsubame-gaeshi have a single charge again.