I'm going to have to jump on board with momforever. It's not because men are inherently messy, but because upright urination is. If you "hear the splash," then you know the main stream is making it into the toilet, but that doesn't mean toilet water won't splash back out. From a standing height, it's inevitable. Toilet water will splash back out onto the rim (or toilet seat if it's down) and probably onto the floor and nearby walls in smaller amounts. Not to mention, unless the man hovers directly over the toilet, the last drops of urine will fall on the rim/seat and floor as velocity decreases.
If men (and women who hover) took this into account and cleaned up after every urination, standing up might not be quite so convenient.
If men (and women who hover) took this into account and cleaned up after every urination, standing up might not be quite so convenient.