In a few points:
1) I would never tell anyone how they should feel about being autistic, since I don't know anyone else's journey.
2) I've had a lot of grief and a lot of difficulty in my life due to my ASD, and part of me wishes I could do what NTs can do so easily sometimes. It's a rough life, and not for the faint of heart, and at times it really sucks.
3) If there was an Autistic Pride like there is an LGBT Pride, I would totally be right there!!
I'm very glad for everyone that is proud of being autistic. I kind of go back and forth, myself. I wouldn't change who and what I am, but it isn't always fun. So I can't blame anyone who doesn't agree with Autistic Pride.