I agree with pretty much all of this -- having just last night experienced extremely bad customer service with the new bank that has my car loan. I wrote them a very angry e-mail. I don't expect to get response, but it made me feel better just to write it.

The only thing I would point out is that this? I think it is unforgiveable to be working in a place that serves the public, but greet them with a glum face

...is not always possible. People in customer service have bad days, too. In fact, I would argue they have even more bad days than most other people, just because of the nature of their jobs. All those years I worked in retail, some days it was just downright impossible to smile brightly and pretend like that particular customer was the highlight of my day. So I would never say that I expect a customer service person to always be bright and cheerful. The most I would expect of them is to greet me warmly and give the appearance of being open to questions and available to help me.

And then if I say no, I'm just looking, I expect them to bugger off and leave me alone. ;-)