[J-Man]

There are a few reasons. The first one being that Creed was a huge success and whenever anyone is on top surely they will get slammed. It's not only with musicians, but with actors, people who play sports, etc. Then there are those fans who "cheer" and support their "team" whether it's in the music biz, sports, or something else. Once the naysayers smear the successors names in the world wide web (hence it can be anyone - even a basement dweller who calls him or herself a journalist just because they have access to a computer), you will have sheep that will follow because they don't know any better. If you are a leader and if someone disses a band you like, then don't succumb to their nonsense and stick to your guns.

Then there is the behavior made by the performer(s). If that person comes off as a jerk, well the response s/he will receive will be negative. If the performer treats people nicely and with respect, then the reaction they will receive will be the same.