The best interpretation of Maggie's hillbilly familiy is that they don't know how to deal with a successful relation, and that mean spirited is exactly how they all seem in that mode of being united to exploit the success. I don't object to their treatment. It's part of the paring down, the simplification of the technique Eastwood uses. He hasn't time for bleeding heart liberalism. Some people, sometimes, are just plain bad. We sure like to quote Rosenbaum, don't we? The observations you add from him are astute. There are, of course, noted critics who hate this movie.