For me I tend to float in and out of games, I play for a while, get burned out, then return.
I don't see any point in rage quiting because of item or build changes, its a MMO, you knew it was coming, anyone who signs up knows that this game, as well as others, are always being changed, for better or worse, its the way the game is.
Who would still be playing this if it was exactly the same as it was at launch? I might have revisted once, maybe twice, but it wouldn't still be selling subs or making money.
I guess my one, and only reason I leave a game, is that I get bored, I have 16 toons to manage, I've been playing since launch, I get burned out, that easy, that simple, but I always come back, for me its always worth returning to see the new things they have cooked up.