Earlier quoted context omitted.
I think you are giving service providers way too much leeway. Service providers should offer their service to everyone, not just to "easy" customers. Service providers should not reject you because you are disabled, because you have a child, because you have a certain religion, or whatever else is the problem. If someone is in the business of transporting people, they shouldn't be allowed to just pick the most profit…
This is someone's personal property we're talking about. Should they forced to shuttle around drunken and incontinent people too? Why should anyone be coerced with being kicked off of a platform and losing (their possibly only) source of income because they don't want piss, shit, and vomit in their car?
Holy red herring, Batman. Are you serious equating drunk people with disabled people who need physical accommodations? The ADA does not have anything to say about mandating accommodations for drunk people.
Separately, people who are incontinent actually, you know, do things to manage their condition (like wear adult diapers as necessary). They aren't just randomly shitting everywhere. Your contrived examples are just downright offensive.