The park nearest to me used to be covered with poop. It was a vicious cycle; I think people looked around, saw the devastation, and figured they wouldn't bother picking up their poop either. There were bags available at that park as well. So sad.
Someone made a big effort to clean the park up, and now it is much better, though there are still mountains here and there. Unfortunately between the big dogs that go there and Thor's massive neuroses, it's still not a great spot for us.