What you say is correct, that is that "E+ seats are provided as a perk, an added benefit for UA's best and frequent customers." What you neglect to say, however, is that E+ seats are available not just to "UA's best and frequent customers" but also to those who while they may not be want to fork over the substantial premium to sit in first or business are willing to pay the supplement to promote from E- to E+. It's not so much elitism as economics.