Why do people ume you're bitter or jealous if you give an honest comment/critique?

Apparently if you don't like or even are indifferent to Twilight, you are jealous of Stephenie Meyer and her popularity. I haven't figured that out. I also hear that we are just being mean to Stephenie and that we haven't read the book(s). Why can't we just give an honest opinion especially when we are asked for it?