Mrs. Shemp and I have combined annual earnings of about $95,000 (before the government rapes our paychecks). We do not eat "caviar en flambe" (I don't think even Bill Gates eats "flaming fish eggs"), and we do purchase items made out of plastic. However, we do NOT shop at Walmart, due to Mrs. Shemp being even more of a flaming liberal (but not with fish eggs) than I am. I don't consider us rich in any monetary sense of the word. We scrimp and save so that we can afford to have a retirement that doesn't consist of eating beans out of a can three times a day, or maybe even worse.
I'm sure that $90,000/year average covers a lot of ground. There are probably plenty of people in town who have little choice but to shop at Walmart. I don't like Walmart, but they have a right to exist, and people have a right to choose whether or not they will shop there. If the majority of townspeople want to block construction, and have a legal means of doing so, then that's OK.