Ha ha! What an American comment! Not only having a gun, but driving your own car to the Airport. Americans love guns but hate public transport! Hilarious!
Americans don't hate public transport, it's just simply not available like it is in Europe. A lot of this stems historically from automotive manufacturers buying up streetcar companies and then dismantling them to force people to drive and also the antiquated rail infrastructure that gives preference to freight cargo over passenger trains.
Not everyone lives in a town with an airport so many people have to travel 100 miles or more to the nearest airport which may not be possible to do via public transportation if you live in the countryside.
It's not an American-only thing. I live about 20 km from the local international airport. It's 1 hour 20 minutes by train (at daytime), 20 minutes by car. Also, there's less walking if I drive. Which one shall I take? Not a difficult decision.
Since some very populous states, including #1 California and #4 New York are mostly no issue, the percentages are even greater in the 43 Shall Issue or better states, a number are getting up to 10%. The percentages are even greater when you adjust to the age eligible population.
So quite a bit higher than "no one", although of course having a licence does not equal routinely or always carrying.