Biggin Hill has been operating as an airport for circa 36 years, has the facilities to cope with B737/A320's etc. but with no regular airline traffic ..... and surviving for 36 years like that!
And it's more of an 'airport' than some of those 'airfields' that LGS6753 lists.
Exactly. Isn't the problem that we see airports as failing when they're not attracting
airline traffic? If you were to fly around Europe you'd find many municiple airports that don't offer many scheduled services, but they're seen as part of the local infrastructure and as an asset to the local economy. Airlines will, of course, stop and start routes according to demand, but ideally every major city should have an airport, just in case anyone wants or needs to fly there. Imagine if we started closing A and B roads just because they didn't attract the same amount of traffic as motorways!
As for who's going to pay for all these airports, well it's not an ideal world and so it's another subject for discussion!