I'm always having to learn new practical skills for work, and getting into things I know nothing about and having to learn them to be successful.
The difference is that the skills you learn from playing games usually are not transferable to the rest of your life. There's some exceptions to this but most of the stuff you learn from complex games are completely fabricated for the game and have very little bearing on real life.... Though, am argument can be made in many cases, such as kerbal. I haven't played kerbal, but I understand there's some reasonably accurate orbital mechanics and rocket science involved. This is just one fairly obvious example that I know of. Not to be confused with a comprehensive list of games with practical educational value.
For me though, I usually don't want to learn anything useful while playing a game, since that's basically what I do for work. So any game, like our example of kerbal will, in all likelihood, feel like more work to me, which is decidedly not the objective I'm going for by playing a game.
I dunno. Different games for different folks or whatever.