If you want to use a street urinal or similar that’s fine by me. If you’ve got to go, you’ve got to go.
I think what most people object to is what’s left behind; the piss and shit, not the act itself.
I don’t want to step in it or smell it or see it. Same goes for dog shit.
You’re not going to catch something from passing strangers holding hands, except maybe a broader world view.