The hypothesis I'm suggesting is that all of that evidence is only evidence when evaluated from the giddily-optimistic view of "what I could have done with all that time if I hadn't wasted it". Not from comparison with the accomplishments of a control group that didn't waste their time.
Oh I see. Yes, that's an important consideration. Not "wasting time" playing WoW doesn't automatically dictate that you're not gonna do some other "useless" activity or that you're gonna get anywhere with any of your "important" projects.
So it's a matter of what you'll give up for it and what it's upsides and downsides are. For me personally, it would almost definitely lead to less exercise, less face-to-face social interaction, less showers, less oral hygiene, less progress on projects that are deeply important to me, etc. I've been there (not WoW, but other addictive video games), and I don't want to go back.
But it might be different for you. Maybe those things wouldn't happen. Perhaps you wouldn't care if they did. Etc. Need more context! Should you play WoW? In this thread, I gave you plenty of considerations that may or may not have been aware of (what you're responding to right now plus an earlier comment). Ultimately though, we perhaps require more information about your situation.
For me: less music, earlier bed-times, less YouTube cycles, no junk food, no MMOs, etc; these all contribute to greater long-term happiness. But should my self of this moment even care about my selves of the long-term? Well, the question isn't really should. The fact is that I seem to be hard-wired that way. I never do anything of mere transient enjoyment or long-term disadvantage without at least a twinge of FML.
The incoherence of our utility function is a direct result of how different indicators mis-align with each other and launch our different selves into an intractable civil war. If my different selves are prepared to carry out the conflict, there's no way to say who's "right" and who's "wrong"; all we may say is that there's a conflict of interests and there will be a winner and a loser.
But I don't think it's in the interest of any of my different selves to have this disharmony. Night guy would much prefer to be able to go to sleep early and enjoy it rather than hate sleeping and instead stay up super late, end up feeling like shit, feeling guilty, etc.
Maybe I'm rambling by now, but I'm just trying to shed some light on the usually mysterious phenomenon that you pointed out: the incoherence of our utility function. And I'm trying to explain what it means for our action, which is perhaps what you're grappling with at the moment.
If people destroy their health for a game, to some extent that is evidence that the game is worth destroying their health for.
Akrasia is systematic failure; rationality is systematic winning.
Short-term, revealed preferences rarely tell us the whole story. Just because somebody destroyed their health for a game doesn't mean that they didn't experience intense, intermittent FML mode the whole time and the vague, trapped feeling so often associated with akrasia, and certainly doesn't mean that they didn't regret it later.
Or to use another example: If you are living in a crack neighborhood in Detroit and the best you have to look forward to is a life of poverty, about a third of which is spent in jail if you don't get killed first, then maybe taking cocaine every day for a couple of years until it kills you really will give you a better life.
Yes. Could be the case. Would need more information about his utility function, though.
We have a deep-seated prejudice against admitting that might be the case.
Most perhaps do, but not me.
I have no problem admitting that for somebody with a different utility function than mine, it might be a good idea to do any variety of what I don't: drugs, junk food, WoW, etc. I'm prepared to dive as deep into the rabbit hole of value subjectivism as you want.
I've avoided playing World of Warcraft because many people enjoy it so much that they neglect other things in their life.
Does that make sense?
How about cocaine?
How about sex? I hear that's pretty good too.
ADDED: Lots of interesting discussion, but no one is getting at some points of particular interest to me. Most answers assume that you have important stuff to do, and you need to decide whether WoW will prevent you from getting that important stuff done. They also assume that your brain usually errs on the side of telling you to do "non-important" stuff (WoW) at the expense of "important stuff".
One question is whether there is any evidence that your brain is biased in this way. I think your reflective self greatly overestimates the probability of success at the "important stuff". I have worked very hard, twelve hours a day, 7 days a week, on "important stuff" for most of the past 30 years. The important stuff never pans out. So it appears that when my brain told me to play Freecell rather than work on that important paper on artificial intelligence that got pulled from the book the day before publication due to petty office politics, or to watch Buffy rather than do another test run of the demo I spent three months preparing for DARPA that no one from DARPA ever watched because the program officer was too busy to supervise his program, or to go hiking instead of spending another weekend working on the project for NASA that was eventually so big and successful that my boss took it over and then tried to get me fired1, or to go dancing rather than work on the natural-language processing approach that got shelved because my boss felt it emphasized the skills of mathematicians more than his own, or to LARP rather than put in another weekend on my approach using principal component analysis for early cancer detection that it turned out some guy from the FDA had already published 6 months earlier, or the technique for choosing siRNA sequences that a professor from George Mason already had a paper in press on - all those times, my brain was using a better estimate of success than my reflective self was.
Another question is why the "important stuff" is important. Fun is fun. On the surface, we are saying something like, "I have a part of my utility function that values contributions to the world, because I evolved to be altruistic." If we really believe that, then for any contribution to the world, there exists some quantity of fun that would outweigh it. And people use language like, "WoW may be fun, but it has little lasting effect." But when you contribute something to the world, if the relevant motivating factor to us is how our utility function evaluates that contribution, then that also has little lasting effect. If you do something great for the world, it may have a lasting effect on the world; but the time you spend feeling good about it is not as great - probably less time, and a less intense emotion, than if you had spent all the time accomplishing it playing WoW instead. So this question is about whether we really believe the stories we tell ourselves about our utility functions.
1. He got to award himself all of the department's yearly bonus money that wasn't awarded to his subordinates, so any obvious success by his subordinates was money out of his pocket.