Whatever you do don’t give up. Keep walking your dog in public and letting people see your dog is a wonderful pittie. I have a German Shepherd and my pittie and I do the same as you. When people walk by I have my dogs sit and wait paitently for them to pass. When people make comments I smile and I think to myself how they are so unlucky to miss out on a wonderful breed based on stereotypes and horror stories.
The best way to promote good pittie’s is to be a great owner. Maybe try your local SPCA. Ours has obidience classes which might be fun to go to just to meet new people and since alot of pitties are put up for adoption might meet some great owners doing the right thing like yourself.
Good luck and don’t let those people let you down. Often when people try to debate me on why I own such vicious type dogs I smile. Then I politely reply, ” I refuse to argue with you on this topic because no matter what I say or my argument you are to narrow minded to look outside your viewpoint.” then I wish them a good day and move on.
What ever you do don’t let their judgment affect you . = )