UNIX is built as a multi-user operating system. You may not use that ability very much, but there's a reason the operating system was built this way and there's a reason these things work the way they do. It is completely valid to point that out.

You're free to say you don't care, but it isn't really valid to brush aside the point by pretending a security model that's there for a reason isn't there.

Also it isn't uncommon at all for an attacker on a server to get access to a regular account and not a root account in their initial vector. It is often too easy to escalate, but do you really want to help them out more?