If my local park is anything to go by, the issue with dogsh*t in parks is mainly because owners let the dogs loose and don't see them crapping.
I've seen two examples of this - the first time the woman was busy texting, and the second was a woman with spaniels busy discussing the breed with a passer-by.
In both instances, they both cleaned up when it was pointed out to them and weren't funny about it - they simply hadn't noticed.
But if you're walking a dog on a lead and find you suddenly have to stop because the pooch is curling one out, then you're going to notice you're outside a school or nursery when looking around pretending the cable-laying is nothing to do with you. There's not many other places that put up finger-painting pictures in the windows and have a massive board written in Comic Sans on their front grass.