From what I've seen on the forums it is true that ToC gets a lot of flak from people, generally speaking.
Personally I liked it, suspect it got a lot of hate just because Ulduar was a hard act to follow. And according to many it came out too soon... I guess that depends how progressed your raid was. Personally I think a lot of WoW content comes out too fast but then you go on the forums and it's wall to wall people bitching about MORE RAIDS NOW NOW NOW WTF DO I PAY MONEY FOR ACTIBLIZZZ RAAAAARRRR!!!