If it is true that a person or persons unknown has masterminded the disappearance of this plane, then (a) we don't yet know who that person is and (b) they will not have been in a sane mind by all normal standards. That's about all that can be said of that eventuality and therefore better to leave criminal and forensic investigators to do their job if and when the time comes. Trying to understand motives or reasons at this stage is somewhat pointless.
Without wreckage authorities are struggling to say more than that they believe the flight was deliberately diverted. Let's leave it at that until more evidence gathers.