There seems to have always been gatekeepers. Well, there was no one blocking the tree of knowledge, but once we were booted from the garden, gatekeeper kept us from returning. Myth? You led with a modern myth, which is a variation of a myth- signs 'there be dragons here' keep many at home. Myth, Belloq was compelled to open the ark, Indy and Marion kept their eyes closed. Why are those that look behind the veil always the bad guy?
If there is a veil, there is a gatekeeper. If there is a gate and a keeper, their are necessarily qualifications for permission to pass. Stardust, the 97 year old guardian was there to keep us from going that way, not to stop that side from coming this way... Myth? Do those that come this way necessarily scare us? If we are scared, does that reveal readiness?
Who are the guardians of doors? GOD. Myth or acronym? Most people just know when it's time to know. If death is a door, we all go there. May all the guardians be wise and kind.
Some doors opened can't be shut by human hands.