Alright, recent discussion has inspired me to work on a video about how to actually enjoy World of Warcraft. Maximising enjoyment while minimising time investment by dealing with the 'work' content efficiently so that you have more time for life.
I would say that they have created an unethical system, but that it wasn't their intent to do so. Humans are very easily manipulated by external stimulus, so when they goal is to increase engagement and retention, it's easy to accidentally do that.