It's not funny at all that it was hated. At start the PvP (that was still a thing) was so unbalanced that many people forgot about it ...unless they rerolled FOTM or their class was the one favored. S5... reseted at one point.... In fact s5 was the most unbalanced season ever created. And at one time (i don't remember season, it wasn't s5) we got a roll back 1-2 days, because of a warlock bug that made them 1 shot people in arena (that was for a good cause, but affected all that played that day...).
Due to some classes having extreme damage, other classes got burried in raids as well... For the first 4 months the game sucked in terms of balance in any department...
BUT by s7/8 PvP balance was nearly perfect... And classes got balanced in general(PvE/PvP).
The thing is, something that started as worst it can be, went out as the epitome of good gameplay ... with immensive story, balance and whatever good anyone could have.
Anyway...
What can upset me...
It's not Legion things...it's WoW things...PvP balance mostly. It it gets unplayable i'll just quit and it won't really bother me...
As much as i can like one thing it's twice i can hate it...
But as WotLK started shit and became the best state of the game, it may happen with Legion too... Getting a season off won't bother me... getting 2 seasons off because of no balance-while templates it's the perfect thing you can create balance (even with the cons that you get no customization which is huge), means i'll just drop WoW and never touch it again...
I even started it because of RL friends... i didn't want to join after a year without playing it...
But if i won't PvP in the end...it's a waste of time...