The "unassigned seating" thing is a little amusing since IME SouthWest actually has like 7 levels of "special" (at least it feels like that) before general seating is allowed.
I probably wouldn't change it (the special priorities) given the choice, but it is mildly annoying when it feels like you're waiting in line for an extra 10 or 15 minutes because you're not pregnant, a veteran, a VIP, etc.