There is difference between "Change" and "Improvement", between "Stagnation" and "Stability". Stability of game systems is very important in RPGs. Also rules were constantly rewritten, not "overhauled". Liked to play your shadow priest as support, mana generator? Enjoyed to tweak your character for different purposes via talents? Combat tables, stat mechanics (GC changed the way how intellect/spirit/spell power works how many times?)? How many stats were "changed" or rather removed from game entirely, just because it was very hard "to balance" around them? It's hard to even find anything in MoP spellbook, because all abilities were thrown in 1 tab into one big mess without even alphabetic order. Not all "Changes" are "Improvements". Oh and change in design of raids: from RPG to 3D Action/Arcade? It's getting cardinally different direction and genre altogether.Plus Blizzard doesn't rewrite the rules with every expansion, they just overhaul system mechanics. Change is a good thing. Stagnation is not.
Poster above me mentioned dailies, I won't even touch them as there will be spam of posts "Dailies are optional!", but I will tell you one thing - the sooner GC and his team will be replaced, the better for the game. I am not sure that damage done to game by Cata and MoP can really be repaired at this point. But preventing damage is a good thing too.