No, it's unsightly and disgusting and people should be prosecuted for it.
I'm a very squemish person but I have to pick up Tilly's turds if I take her out no matter where she does them, (she's usually good and waits til the park where there's a bin not far from her spot) and it hacks me off when i see people let their dogs turd and don't pick it up. In all fairness, it's rare that I see this. (Especially after I've had a word or two, I'm particualy shrill and annoying when i see it happen).
I've actually had to pick up some other mutts turds once when walking Tilly and my godson. I was scared he'd end up rolling face first in to it and I would have hated explaining that one to his mother.