I'm somewhat dubious that you carried openly in an airport unless you were wearing a uniform at the time or this was a LONG time ago.
Perhaps you're unaware it is perfectly legal to carry in the *public* areas of airports. Go back and re-read his post and you'll see he pointed this out. Sure, you get stares. That's part of the problem: people assume that you're some kind of crazy person just because you're openly carrying a firearm because they've been *conditioned* to think that way.
Nobody is going to attack you in an airport
Unless you somehow live *in* the airport, you must walk from the airport to the parking area to get your car and go home. Predators in the Atlanta area know that people coming from the airport are almost certainly *unarmed* because it's extremely difficult to carry a firearm with you on a trip. Many people are robbed, beaten, and raped in these areas because of this. Criminals aren't uniformly stupid; they look for prey in areas where resistance is unlikely.
I don't think it is unreasonable to register firearms
And if I thought for one moment the government would be responsible and exercise restraint in the area of personal ownership of firearms and respect for the *individual* right to bear arms in the 2nd Amendment, I wouldn't mind it either. The government, however, has not demonstrated itself worthy of said trust. A sufficiently-liberal judicial branch could quickly nullify the 2nd Amendment; it's not like they haven't tried before, and liberals show no signs of abatement in this area. Without 2nd Amendment protections and armed with a list of gun owners everywhere, the government would have all it needs to strip law-abiding citizens of their firearms or jail them if they don't comply. Meanwhile, unregistered firearms in the hands of criminals would remain in the hands of criminals, giving them the upper hand in any altercation with law-abiding citizens.
*require* safety and competency training, and to conduct background checks.
I'm with you on the safety training, but be careful when defining "competence". It wouldn't be hard for an anti-gun lawmaker to define "competence" in such a way that it's impractical for anyone to qualify, thus effectively ending private firearm ownership. And if you think they wouldn't try, just look at what anti-gun lawmakers have done in states and cities where their anti-gun laws have been shot down (pun intended) by the Supreme Court: crazy taxes on ammunition, onerous procedures and lengthy wait times to obtain licenses to deter all but the most determined from obtaining their firearm, zoning laws that make shooting ranges and gun stores impractical to locate, and so forth. Background checks are already in place.
In many ways it comes down to trust. Firearms owners like myself simply don't trust the government to respect our rights in this area due to a lengthy history of assaults on said rights.
There ARE crazy people out there looking to shoot up schools and movie theaters and public gatherings.
There are millions and millions of gun owners out there who carry every day and *don't* shoot up schools, theaters, and so forth. Would you tread on the rights of 99.9% to try and stop the 0.1%? I'll remind you that, if you follow that logic, you'll need to outlaw driving, as it kills more people every year than any number of crazed gunmen. More people drown in public pools, or die eating fatty foods, than have ever been killed by a nutjob with a gun.