I’m not sure population is as much a factor as location would be. Although maybe it’s both? Orlando is a super touristy area, a lot of people travel there to stay there. Yeah, you get a lot of people flying to Orlando, but travelling somewhere else to stay, but a lot of tourists stay in Orlando, Miami, Tampa. An area could be super populated, but if that’s not where all the tourists/majority of travellers want to be, what would the point of having an airport in that area be? That’s what I’m trying to get at. Also, airports are expensive. You got the actual building, ATC tower, runway, lights, then you need staff. And if you want to fit multiple 737s possibly then you would need a considerable area to actually make into the airport. They need room to park and room to take off, all that. Also, they are loud. Not many people want to live near one. So it could depend on town/city boards if they want one I think. ~~~~ Which is why I mentioned airports being in tourist areas. The city is going to build this considerably large airport, they want the people landing to spend money in that city to make up for the cost of construction. So lots of restaurants, tourist attractions, you get the picture. Edit: considerably large as in big enough to fit a few passenger planes. Not large as in international airport.