It depends on how you define doing the right thing. If you mean telling drivers to be accomodating of passengers with disabilities, then yes I agree. If you mean fielding an entire discrete service of vehicles across the world to service a small, non uniformally distributed number of users without actually employing their drivers; that's a bit harder. I'm not saying that Uber shouldn't deploy such a discrete service, but I'm not sure it's fair to say that ADA compliance in this context is cheap or easy.
ADA compliance is almost never cheap or easy. That was the knock on the law when it was being debated and any business owner will tell you it's still every bit the costly nightmare people said it would be at the time. It's a terrible law and most of it should be repealed (the rest should devolve to the states, which unlike the federal government have the constitutional authority to impose it), but the fact remains that courts have upheld it and it is the law. There's no reason one taxi company should have to follow it and not another.
