I found it amusing that customers were annoyed with the author for charging for "nothing". If the author didn't solve your problem, or if you could have done it yourself with no help, why did you buy it?
This leads to some things like perceiving less competent workers' time to be worth more than more competent ones' (because they take longer to do a task, therefore they should be paid more), etc.
They were annoyed because nothing had actually been copied. It's like paying for a product and getting an empty shipping box in the mail.