because the 30% - 20% "older crowd" is really gonna boast sales and grantee more sequels? ...
Actually if you look at the business model, yes.
See, if you release a game that does not attract the older crowd, they will eventually stop buying the product. You will lose your loyal customers in the hope that they are replaced by new customers.
Who you then don't treat well, so you lose them too. Think about it. People thought Ob. was dumbed down compared to MW, and others thought Sk was dumbed down compared to Ob... Downward spiral.
In the meantime, although the amount of money you are making is going up, you keep losing customers. Your sales are entirely based on your ability to find new customers, without looking after the old.
Oh and don't forget that your ex-customers are now probably badmouthing your product. Instead of saying good things about it.
Sooner or later, something gives.
So to end that rather dire story: I have friends who are 17 and 18 who think that TES is a pointless and truly awful game. To an extent, I agree with them. The concerns they bring up are entirely valid, and are mine too. Besides that, I play it to relax and have a sight-see. I don't play it because I respect it as a game.