My take on this issue is that while I would prefer to not have to worry about "land mines" at any time, I especially take umbrage when the deposit is left in an area where people will be running around. If a dog poops on the boulevard that's annoying, but when people let their dogs crap on a sports field or a children's playground or school yard, well that's just plain irresponsible, rude, and unfair.
Digressing into an anecdote for a moment, back in Little League tryouts when I was a kid, I picked up a grounder that went right through some poop. I knew that ball was covered in the stuff, but I was being graded for the tryouts so I just threw it back. Don't know if that helped my score or not, but now there was poop not just on my glove but on one of the coach's gloves as well. I figured the evaluators watching would be impressed with my concentration.
While I'm pointing out irresponsible behaviour, here is another obvious one that is damn annoying and many others have taken umbrage at I'm sure. It's the leaving of furniture on the boulevard. This can be just as unpleasant and certainly more unsightly than some dog poop. C'mon people, don't be leaving your crap lying around for the rest of us to deal with!!