The negatives for legalizing it would outweigh the positives.
Life is a big positive, if you are alive because you were allowed to excercise your right to bear arms that would probably be a good thing in the minds of most people.
Are you to wait for a single Air Marshall and pray that your plane is one of the 5 or 10% that has one onboard? What if the Air Marshall is the terrorist?
I understand that arguement that passengers have stood up for and faught valiantly and sometimes even successfully to stop a hijacker, I also understand at times it didnt work out so well.
Do your rights end simply because you get on a plane? I understand the government has a concern for the passengers and for whatever the plane could be flown into but does that arise to the level to negate or in someway modify the 2A? At some point should not the honorable citizenry be able to be trusted by its government to act honorably?
A lot of tough questions and I dont pretend to have all the answers but in the end at some point we have to be able to trust at least some citizens to be able to act lawfully and if we cant then the problem with the planes is really small fry. Are we to go from a nation where you are innocent until proven guilty or become (continue to be) a nation where you are guilty and never capable of being proven innocent concerning if you can be trusted to be responsible...
Weighty questions indeed..