Wow, that got out of hand quickly.
I've worked retail, mostly as a supervisor. But I've had to run a register, and I usually had to help count drawers at the end of the night Counting large sums of small bills is annoying. Angel's initial post pretty much said she was annoyed. That is perfectly reasonable. She didn't complain or refuse to the customer, she just wanted to vent ever so slightly about it later. Each and every one of you would have done exactly the same thing, so the "do your f$@#ing job" rhetoric can probably be dialed down just a tad.
How it spiraled into ruminations on parenting and professionalism I have no idea, and I have no particular stance or comment except for this. Angel is right about one thing, working in retail changes your perspective on the people you deal with day to day. There are good employees and bad employees, but they are all real people mostly just trying to get through the day without a customer yelling at them. And being yelled at because someone is trying to save 50 cents on a box of file folders is never any fun. I have the experience to back that one up.
I don't work in retail anymore, and I'm pretty satisfied with the decision to move on. But it taught me some pretty decent lessons, and whenever I'm buying something in the store, I try to be polite with the workers, maybe even smile every now and then. Just remember that they're people too.