A spaceport that doesn't have any commercial flights is probably a worse waste of money than a sports stadium. People will drive for a hundred miles to go to a sporting event if they care about one of the teams playing. They'll buy gas, they'll buy food, they'll pay admissions, they'll go to the bars and the restaurants after the game, they might even look for a hotel to stay in before going home.
A spaceport in rural anywhere only makes sense when there are flights, and for it to be paid for by the taxes collected in an area the area needs to derive an actual benefit.
As for a town of 6000 with only 21% bachelors degrees, that is absolutely no surprise at all. A town of 6000 people probably doesn't have very many jobs that need bachelors degrees. There will be a doctor or maybe a few, there will be some nurses. There may be a dentist. There will be at least one pharmacist. If there are schools the teachers will have degrees. There will probably be a few business owners that originated in the area, left and got their education, and came back, possibly employing some in the town. If anything, 1/5 of a small town having bachelors degrees is probably rather high.