I think it's hard to pay for something like P.F. Chang's when I know I can pay less and get better tasting Chinese food elsewhere. You make a great point about the diversity of Chinese regional cuisine. My family prefers Northern Chinese food (noodle soups and bao!) as well as Taiwanese fare (including the XLB dumplings that are very popular worldwide), so we don't eat deep fried saucy food that is considered "American Chinese food."
The first time I ever had that kind of "Chinese" food was at Panda Express (and yes, their Orange chicken isn't bad but it's not what I grew up eating as Chinese food).
Sometimes I do want to pay for ambiance, but I usually want a delicious meal more than I want fancy decor and a formally trained wait staff.
And I'm probably one of those people who's too picky about her food. I don't like Taco Bell because I know my favorite taco truck as well as various taquerias nearby have 10 times better tacos (and my favorite meat choice, lengua) for a better price.