I'm curious on why it is that some authors are so interested in the inherent value of games. By your definition, I only play games based on their subjective value. I play games if they are fun. If they are not, then I do not play. I spend very little time analyzing what the inherent value of a game could be. That is not what drives me to decide what game to play that night. Sure, if I knew that psychologists had analyzed Doom and found it to be mentally damaging in a profound way, I would be less inclined to play it. But it is very difficult (I agree with your 1000 year test and discovery) to analyze, and in general I do not even concern myself with such.

On the other side of the spectrum of games, if the primary reason you play games is for their intrinsic value, this is a rather silly way to lead your life in my view. I spend my time in two categories -- activities that improve myself in some way (very little actually), and activities that I deem fun and enjoyable (where all my games fit in). Why not spend your time enjoying your life, rather than spend it wondering whether it is intrinsically improving you or not. If you followed the latter, then I see you spending many a gaming hour playing "algebraic flash cards" or vocabulary-strengthening scrabble.

I suppose you could say I live my life 50% just indulging in activities that I find fun and pleasurable. But goshdarnit, I'm certainly enjoying my life! That doesn't mean activities can't be both fun and have some value. For example, I play two sports, golf and paintball. Golf is much more likely to be the "good" sport that inherently improves you in some way (improves social skills, mental toughness, peacefulness) and paintball the more "useless", but they are both damn fun to my mind. And I play them both equally solely because they are fun. If I unconsciously am bettering myself in some way, so be it. But in all honestly, I don't really care, and it has 0 effect on which I choose to engage in when I wake up on a Saturday morning.

I think it all comes down to why you live. What is your highest priority in life and what do you want to do with it. For me, it's to be happy. Engaging in activities that are fun, linearly increases my happiness. Improving myself is secondary.