In the doctor scenario, we've had adult diapers for a long time. Your solution is you let them pee in your car?
And your solution is they shit themselves on public transportation?
I mean, I'm 100% for better public transportation and urban centers designed around walking, but let's compare apples to apples here.
They didn't make a straw man argument, they had a point. It's a genuine issue and they deserve better than a flippant remark telling them to make grandpa wear diapers so he can piss himself on his walk from the bus stop.
My point is that the "piss in the car" comment was mean, thoughtless, and added nothing. If grandpa is incontinent, then he'll wear diapers regardless of the car or the bus.
Your comment was either a.) implying that messing themselves in public was better than in relative privacy, or b.) if you use a car, grandpa doesn't get to wear Depends.
Take your pick.
It might not be what you meant, but you were too busy being a jerk to notice that it's what you said.