"Necessary" because Linux's security mitigations are unacceptably insecure for the 21st century. As it stands, I have to completely trust applications before I

"Necessary" because Linux's security mitigations are unacceptably insecure for the 21st century. As it stands, I have to completely trust applications before I run them, and there's literally no reason for that to be the case - sandboxing is a straightforward mechanism, not a tricky problem like Traveling Salesman.