I don't think anyone is beating anyone over the head. But this seems to be a case of expectations not meeting reality, and the general wisest course of action is to listen, learn, and adjust expectations OR the situation to avoid the same outcome again. In the OP's case, her expectation didn't match reality and if Tai Chi is something she still believes is worth pursuing, better to pay for the quality and type of instruction she wants, since her preferences and expectations in this situation don't seem the type to be readily or easily changed.
It's the same reason I don't eat steak at a diner. I am picky and particular about my steaks, and you get what you pay for around these parts. Since I'm not about to adjust my expectations of the quality and flavor of my steak, I suck it up and pay for the quality I want, rather than getting mad at the diner for not being an award winning steakhouse