I've seen good petcos/petsmarts and terrible ones. I've seen good mom and pop reptile stores and ones that made me cry.
Generally, and especially 10+ years ago, MOST pet stores, chain stores or not, were not that great so a bias has been established.
I agree though, when you find as good one, try to support them if that's what you want to do.
Did you work at Exotic Pets with Ken Foose?