I think adding creative skills and skills of physical mastery both make for more worthy pursuits. This would cover your jazz piano and unicycling and would exclude the Dota example. It also excludes reading fiction, which I think is not much different from watching a movie or playing a game.
Would it not also exclude learning a foreign language, though? Not to mention that it's pretty arbitrary that those skills are considered worthy, but others aren't...
I don't think I can formalize it easily, sadly. I guess I hate Dota because I play it even though it frustrates me most of the time, and it doesn't leave me with any lasting skill other than itself.
