I am of the opinion that businesses are defined by how they handle the exit of customers more than by how they handle take-on of customers. A customer being difficult to manage or not profitable still deserves a professional exit.

These sorts of customers are not, however, automatically "stupid customers". They are "difficult" or "non-profitable". In my experience, a user simply being "stupid" doesn't in itself mean that you shouldn't work with them - in fact, often with a little bit of work, they might even become a reasonable repeat customer.

Like a lot of people who have had customer facing roles, I have enjoyed reading notalwaysright (and the older http://customerssuck.livejournal.com/). But I have found over time the postings to have become more deliberate funny-making or actually problematic from an equality point of view.