My biggest concern would be hygiene. Particularly with guys. We all know their aim is not perfect on good days. And that's with a "controllable stream".
Imagine the uncontrolled variety. Add that most porcelain is white. And white fluids on white are not particularly easy to spot. I don't want to be sitting down to take a dump and slide my butt against some w@nkers nutt butter thanks.
Sweat from someone else's arse on the seat is just as revolting as nutt butter.
I always have wet baby wipes handy at work and in my car.