I feel your pain!
You really do have to develop a tough skin, and just be really friendly about your lovely pit. If you conduct yourself like there isn’t anything bad in the media about pitbulls, and treat the breed like it doesn’t have a bad reputation, it really helps..
For example.. I had to take my baby Rocky to the vet. He’s a big dog, strong. We came in early, and there was only one other lady and her small dog in the waiting room. He was a pug mix. Well, Rocky is naturally curious, and was pulling to go smell this dog. The little dog also wanted to meet Rocky. The owner was cautious though, and giving Rocky and I the stink eye, due to his being a pitbull. I gave her the biggest smile I had, and said, “Wanna let them sniff? Once Rocky meets him, he will calm right down!” I was so positive, (and in her mind ignorant I’m sure) she was a little stunned. So stunned in fact that her dog got that last bit of leash to come over and sniff Rocky. Rocky took a couple whiffs of the runt, turned around, and walked to my mother who had sat down on the other side of the waiting room, and acted like a perfect gentleman after that. =)
Oh, I forgot to mention, the lady was very friendly to me the rest of the day! She said Rocky was beautiful, and very friendly. Woo! Won one over for the team! Haha =)