Regarding your second comment, I'm not sure if you're suggesting that focus strategies aren't viable business strategies?
Not directed at me, I know, but a couple responses.
1) Just 5 years ago, this didn't seem to be the fate of consoles. Consoles were the uncontested rulers of the gaming universe, and the expectation would be that they would continue to grow in to new market segments over time. It seems we've all essentially conceded that this isn't possible any longer. That's not just a change of abstract expectations; it also really affects the long term strategy of the software publishers, and it's why they've all had to dramatically scale back the number of console releases.
2) I think focus can be fine, but I don't think the types of consoles Sony and Microsoft build are very well suited for that approach long term. Things like handhelds might possibly be capable of focusing on a particular demographic, because it's easier to keep production costs down. But the PS/Xbox consoles are built with the biggest, most expensive games in existence in mind. No, I do not think that lends itself well to a narrow demographic.
I think the only plausible method for consoles to continue along this path would be for the systems to have increasingly high cost of ownership. I think the better approach would be to try to win the "casual" consumers back, but it's probably too late to do that significantly this generation.