Well, if you look at the airports that Southwest serves, I think you'd say that many of those airports meet the requirements that you suggest. There seems to be a fair number of airports like this in the northeast, including Manchester, NH; Providence, RI; the former Pease AFB near Portsmouth, NH; Islip, NY on Long Island.
Whether there is an "abundance" of such airports and whether they are "ideal" is well beyond my ability to judge.