I'm not trying to say that WoW should go free to play, it's just that this argument I read here and there is tearing at my brain and I have to attack it.
When you go out for a movie and you:
Pay for the popcorn, the money goes to the pop-corn company and the container distributing company.
Pay for the drink, the money goes to the drink company and the cup distributing company.
Pay for the movie, the money goes to the movie studio, cinema upkeep and cinema staff.
So with almost 20$/movie you're paying 7 different entities to watch it, they can't afford to make it any cheaper, regardless of how many hours of enjoyment you get out of it. Those entities have to be PAID.
If 15$/month didn't pay for all the WoW developer salaries, hardware and development costs it would cost a lot more, but 15$/month does pay for them, so it doesn't cost a lot more. However, a movie ticket doesn't pay for your popcorn, doesn't pay for your drink, it pays for the studio and cinema upkeep costs, the popcorn and drink are two different entities part of your "night out" scenario.
The only way this comparison could make sense is if you're comparing the monthly cost and a pool table, or a babyfoot table, or a monthly fee and a fleshlight.
Or hey, I can go all dramatic here and say: well, a WoW "night out" costs me 10$ each time I play it + 15$/month, because whenever I play I have to have a drink and some snacks too.
You can't combine the price of a movie in your "a night out" package then compare it to a monthly fee, they're three separate things.
I'm sure I was trying to make a point somewhere in all this.