Considering more and more aircraft is fly by wire and most pilots get their "air time" in sims, is there not a advantage in building a mock cockpit at the back of the airline with a backup pilot to take over when other protocols are met? All this is doing is highlighting how one person beit the president or prime minister of a country, judge's, GP's, practically anyone including a pilot can steal some or all of other…
Same thing with the doors. They got strong locks and protocols to use them in response to rare events, but it makes other rare events harder to manage.
We generally live in a pretty trusting world, which enables many things, including violations of trust with major consequences.