It just goes to show that all the security BS in the world won't stop a person or persons from doing what they believe is necessary whether it be for religious reasons, political motivation or just pure insanity.
One partial solution is to remove the toilet doors, then we shall see whom has a genuine reason to go into the smallest part of an Airliner:-)
As has been indirectly mentioned here already commercial pressure is everything when it comes to an Airline, safety takes a second place if it can be done so.
Wmk2