By that logic, forcing any name on a child is selfish, so they should pick their own name, since they are the ones that would have it. Although, in that case, temporary names would probably be a thing, so I don’t really see the issue (or you could use other cultural naming conventions like that, but that is one that exists.)

Unless your argument is nonconformity is selfish? I personally think some people will find a reason to make fun of another person, but nominative determination does have its appeal if you don’t believe that.

All names were unique at some point, but that’s a moot point. Eventually they will either become more popular or less popular.