Even when they don't miss, they can splatter. Of course, that's maybe less so with urinals. And I think there's a stereotype that men will live with a bigger mess and aren't as fastidious as women, so they will let things drop and leave them, etc.
Re: the toilet paper:
I've discovered that the vast majority of restrooms that I think are icky are actually cluttered with little schnibbles of TP, or pieces people dropped because it ripped off too soon, etc.
I do my "service to humanity" thing and scoop them all up, and wow! The washroom looks fine!