You argument is biased and non-factual. Default ssh measures keep un-trusted entities from gaining access, normally. Conversely, once access is granted by the admin to trusted entities, the normal UNIX permissions continue to provide means by which access to the file system is limited by user permissions. Thus, simply by an admin granting access to a system, your (hypothetical) arguments become false and pointless to discuss.
You must be kidding me.
My "argument " is a question. My "hypotetical arguments" consist of me asking if there is some thing stopping people from scp'ing things to my computer then running them.
You talk like phishing and privilege escalation weren't things that exist. Have you ever managed any public-facing service of any importance?
Actually, those types of questions are called leading questions. Making a point based on a hypothetical can not be logically used to make a factual point without it being a bias, even if you phrase it as an "unknown", or question. Your last comment here shows your tendency to blame and use biases for making arguments, which is unfortunate given you appear to be asserting authority on matters of "public facing" servers. You know what they say about making assumptions.
I would note that using biased arguments is an inefficient process in most cases. It's akin to recursion of a process which, in my experience, has brought many a more server to its knees than a hypothetical threat from double authorized access (hash + key).
