For many, the cost of a game -- the initial purchase plus the monthly fee -- is simply assessed once, then never considered again. You have to pay something, after all, and you don't really have a choice if you want the content. Obviously, this doesn't take into account free-to-play games, but some people believe that you get what you pay for.
But there is also the consideration of value over time -- was it worth that fifteen dollars for the month if you didn't enjoy the gameplay? If not, then why not? What would be worth that fee? Is it fair to say that sometimes you have to absorb the cost of a game you disliked to find out for yourself that it wasn't worth playing? Are there any games that you're happy to pay for, knowing you're helping ensure the maintenance and further development of the title?