End game story is poop.
Talent builds are totally ruined.
Difficulty is ruined.
LFR.
Tol barad is a joke compared to wintergrasp.
I’d add LFD and heirlooms but they were introduced with wrath.
Pretty much the only positives with cataclysm are new class options, hunters now using energy… and maybe new BGs. It is interesting to see the old world changed and all their stories updated, but you don’t need to stay long term for this. You can sub one month, quest all the zones you want, then promptly unsub.