The weak link will always be the necessary interface between a ground based operator and the aircraft. If somebody can design it somebody else can get around it.
As for single crew, what happens if this person flips out. Didn't this happen on a Fedex aircraft some years ago? What happens if they become incapacitated for whatever reason.
Besides, at the moment people are paying the airlines thousands to sit up there, i'm suprised there not asking for more of them.