Its not really a little comment when she gets so much attention. People will just believe her word to be gospel. I don't see any jealousy at all. And, really, I agree with him. Rowling's getting attention more because her books were the right thing at the right time, not because they're the best things ever written. Its not that she's a bad writer, but she shouldn't be seen as some wonderful person who singlehandedly saved the Fantasy genre.
...and I'm also slightly confused as to how she could possibly not think she was writing fantasy.