Only Tobold can say whether spending 5,000 hours playing WoW was the most cost efficient way to have fun during his leisure time over the last 5 years. We will have to take him at his word when he tells us that such a length of time has not had long term ramifications on his social relationships and his health.
But I don't think that this is good advice for the majority of people. The majority who have clocked up that amount of time on a single game have moved long past the point where they are having real 'fun' and are simply addicted.
Further, I am amused by Tobold's comparison of WoW and Dragon Age. His thesis seems to be that:
time taken = fun had
I would think it would be more valid to say:
time taken - time spent on repetitive seeming tasks = fun had
Of course, this depends on what seems overly repetitive to the individual. For me, the "fun had" side of the equation for a game like WoW is well into the negative. For Tobold, it's well into the positive.
I've never seen a picture of Tobold, but I am struck by the image of him running ceaselessly in a giant hamster wheel, tongue gleefully hanging out to one side. A big red button may be pressed that sometimes dispenses cheese. The frequency of cheese dispensation is inversely proportional to the number of cheese morsels that have been dolled out to date. Bemused scientists look on from the sidelines making notes in their clipboards, wondering whether this beast of epic endurance will ever tire of their test.