I feel like a lot of this is driven by a bias towards the unknown. You don't know all the security issues in something new or even something old that doesn't get the same level of testing as Linux.
I would trust security hardened Linux over all of the suggestions any day of the week. Better the devil you know.
I think we have different definitions of security. Your definition may be more theoretically secure, in your mind, for the novel and interesting solutions. My definition is about a hardened, time-tested solution.