Common sense.
Travel is a right. The conveyance used being a right is stretching this beyond all belief. Under your logic any old Billy Bob should be able to hop into the cockpit of a 767 and see how far down the runway he gets...without the benefit of the FAA checkride.
Sure Billy Bob could hop in a 747 if he happened to have one.
Prohibiting based on a conveyance is the same and prohibiting travel. Walking from Florida to Colorado is not practical.
If the same restrictions were placed on other rights everyone would be up in arms.
Taking a check out ride in a 767 would involve theft, unless the person is rich enough to afford the cost of buying it