I agree with that. But:

If the service animal is medically necessary for a single human, then it's between two individuals. If the service animal is necessary for multiple humans, it becomes a different question. Both arguments are valid and because of this, for any service animal, this argument becomes moot: no one human's imperative need takes precedence over that of one or multiple others.

If this were about pets, I would not be making such an argument (although I do travel with my pet in-cabin, so I'd probably be making some argument, but from a completely different standpoint), but it's not; it's about service animals.

Of course, the whole argument is irrelevant, anyway. The airline and the government enact policies and laws to deal with these situations, and if you don't like how it's handled, you need to take it up with them, not with the passengers who are merely complying with existing policies/laws.