> rather behind in the foundations. It's a single user system with no real security
I believe multi-user systems are actually an ancient, outdated rather than a "modern" concept. It made sense when computers were huge, expensive and many users shared one even at work, let alone at home. Nowadays computers are almost never shared. Even when people used to have just one home PC per family (during pre-Win7 days) they mostly preferred to disable the sign-in screen and share the whole environment.
Nowadays multi-user OS facilities definitely help to build security but they were not designed just for this. Modern security can be done better without an OS-level concept of a user.
I believe multi-user systems are actually an ancient, outdated rather than a "modern" concept. It made sense when computers were huge, expensive and many users shared one even at work, let alone at home. Nowadays computers are almost never shared. Even when people used to have just one home PC per family (during pre-Win7 days) they mostly preferred to disable the sign-in screen and share the whole environment.
Nowadays multi-user OS facilities definitely help to build security but they were not designed just for this. Modern security can be done better without an OS-level concept of a user.