The distances involved are one factor. The bigger part of it most likely is that most of us are not going to drive more than a couple hours to see someone from inside a game. Not speaking for anyone else here but I for one am not a large party kind of person. I don't like going to large gatherings and hanging out for hours on end.
Highly understandable. I don't like mass gatherings, either, and I guess in the USA they are way bigger than here. Finding a fellow AH'er in some WW2 event with tens of thousands of people is equivalent to the needle in the haystack.
What I wanted to point out with my calculations, was to show that statistically there should be a couple of AH players living within a half an hour's ride. It shouldn't be too difficult to announce e.g. on this forum one's willingness to meet other people in a certain area and then arrange the gathering to a nice place, be it a cafe, pub, restaurant or your own backyard depending on the agenda of the meeting.
The first fellow AH'er I ever met was Kanttori. In fact we had already known each other for some months when he heard about AH and asked me to join him to play. He's got a large network of acquintances whom he used to talk into trying this. After about six months of playing I gave a party for my 40th birthday inviting all squad members, too. That was the first time I met people whom I had learned to know in cartoon skies, our squad leader coming from 400 km away.
On our cross squads bulletin board forum we also have a sticky with people's names and addresses. Every once in a while someone starts a thread telling he'd be travelling to a certain town asking to meet local AH'ers. As Rondar hinted in his post starting this thread, it's mostly grabbing the opportunity, in his case his daughter living in the same town as Heeler.
My door is always open to any fellow AH'er passing by.