IMHO, we do a whole lot of talking about the typologies and theories, but we do a pretty poor job of translating that into useful day-to-day practices.
So the more I think about it, and reflect back upon the typologies over time and the theories that came from them (and contrast them with the more detailed and specific work we are starting to see from academics), the more I feel like it's all kind of like Malcolm Gladwell.
You know, middlebrow. Not really right. And allowing people (incl. me) to feel special and smarter than they are by discussing it. "Hey, did you know that if you spend 10,000 hours doing something, you'll be totally awesome at it? It's a law, like gravity! I READ THAT, SO IT HAS TO BE TRUE!"
It's not true ... but it does feel that way, doesn't it?
It's just strange- I made the usual joke about sorting people into groups, above, but it's kind of true. Imagine almost any other area where you'd get people kibitzing about how there's really 3 or 4 things that motivate people (and without empirical data). I don't think that would fly!
It doesn't mean it can't be useful. I think that good game design has come from it. But the underlying typology and theory always seem to be a lot of "just so" theorizing that sounds great until you really start to examine it closely.* It reminds me of Freud- sure, there's a lot of really good art, and literature, and critical analysis that owes a great debt to Freud. But I wouldn't recommend going back to Freud's "science" for treating schizophrenia.
Or maybe not. Who knows. Life is a boundless mystery.
*Again, I think that there's a reason that we keep seeing the amateur typologies re-occur, with different variations. It's people trying to make sense of the issues that they are having. After a while, though, a lot of it just seems dated- sort of like hearing a standup talk about airplane food.