I too remember endless threads of:
*TBC is shit compared to Classic
*These raids are f*****g overtuned*
*Fix (insert class here) BLIZZ NOW FFS* x10
*FIX BUGS ALREADY BLIZ FFS cant raid because you suck*
*Flying mounts made me quit, good job BYE!*
*FIX SHIT ARENA UNBALANCED ! THATS NOT REAL PVP*
I could go on forever
.
So yeah, tbc was way more hated during and at the beginning of wrath.
Later on though , dunno why ( prolly nostalgia but i am not going to say it was 100% that ) , people started thinking back only at the first 3 bosses of kara and say it was nice.
Good day !