To be fair, cataclysm was pretty well received initially up until the point blizzard started nerfing everything left and right and making strange decisions. The main reason that people had an issue with regarding the zone overhauls was the fact that all of the original versions of the content was gone forever, which is a problem we have a solution for these days that we didn't then. Plus expansion based zone updates would be handled through phasing and this not become active until they were relevant to the story, so you could level through a zone, come back at a higher level to see how time has passed and then talk to the bronze dragon lady if you wanted to go back in time and finished up things you had left undone which is very different from cataclysms "THIS UPDATE IS THE NEW EXPERENCE, FINISH THE OLD STUFF NOW OR NEVER SEE IT AGAIN."