Honestly i can't exactly tell WHY i hate this update so much, I just do. Combat feels LESS fun for me since they started. It may be a little better now though. I gave up on MC about two weeks ago and moved over to other games.
I think the biggest issues for me was the simple fact that rather then doing things to make the mobs more interesting they are just NERFING the living crap out of EVERYTHING the player has.
I probably wont be back. It may work great for PvP but "make you do less damage and take more" is not a fun way to go when making a game more challenging.
I would also like to add i dont want to see these changes removed entirly... and i know that seeing all the previous updates that server owners will have some power of the magnitude of these changes, whether it be via settings or command blocks.
I really just cant be bothered to play the game in this current state. I don't give a toot about PvP... But that seems to be about all anyone cares about anymore. Maybe the games just outgrown me?
regardless, i hope it works out and the game does well off it. I hope they give us some new tools so people can find better things to make then PvP minigames.