I think you're rather missing the point. What I took away from the article is not "choose better entertainment". It is that many people waste the time of their life on things they do not even particularly enjoy, simply out of habit, and that it is a good idea to give some thought to how you spend your time, and to re-evaluate your choices periodically and see if they still make sense.
This is valid advice and a good reminder for any time investment, whether entertainment, work, your own business, or, as you say, improving the world. Replace "watching Lost" with "fixing leaking roofs in Mexico" and the point still stands - there are more and less effective ways of improving the world, and if you do not take the time to re-evaluate your choices, you will waste time and energy that could help more people. Sure, you could go and become a carpenter in Mexico and build houses. Or you could create a small business loan system to lend money to a thousand carpenters in Mexico. The point is, be flexible and free to change your direction if you see a better way.
I think it's just because first, entertainment is an example anyone can relate to, and second, he's a game developer, so entertainment is the context he is working in.
And look, less than half way in: "... The same metric can and should be applied to all activities: is the experience worth the irreplaceable hours of your life? Not just consuming media, but hobbies, travel, acts of creation and destruction ..."
This is valid advice and a good reminder for any time investment, whether entertainment, work, your own business, or, as you say, improving the world. Replace "watching Lost" with "fixing leaking roofs in Mexico" and the point still stands - there are more and less effective ways of improving the world, and if you do not take the time to re-evaluate your choices, you will waste time and energy that could help more people. Sure, you could go and become a carpenter in Mexico and build houses. Or you could create a small business loan system to lend money to a thousand carpenters in Mexico. The point is, be flexible and free to change your direction if you see a better way.