[onion2k]

I think there's a little confusion around what the 'customer' is here. You seem to believe the customer is the end user. I think of the customer as the person paying for the software. When someone buys some software they usually want it to be reasonably well written, especially if they understand the development process. If you're supplying software to a customer who understands the development process well you'll often find they're more than happy to pay for additional time to do things like refactoring, testing, documentation, etc. The really good customers insist on it and will stop buying from you if you don't include it in the cost.