I think fiction writers are like that. I recently asked a neighbor for help w/ a book I'm starting - and the first thing she asked was if it was fiction.
That said, I also had a friend who wrote non-fiction books (and wrote for the NYT and was teaching to boot) and he was pure journalism.

I guess we all have our predjudices - I like good writing and interesting stories whatever......

PS - I agree that her response was rude. She could have just said Thank you to your compliment and left out the put-down.