I don't think PC gaming is "more adult" by default, I think it's more a case that you can buy a console with zero knowledge of what you're doing, plug it in, and it works (most of the time), also Consoles tend to be aimed more successfully at children, and are much cheaper to get into than PC's.
I know a number of youngsters who have PC's which are used at least partly for gaming, but they tend to be the kids of parents who know a bit about PC's, and still tend to have consoles to play games with their friends who don't have a savvy parent.
At the moment with the likes of Steam making it easier for a small company, or even individuals to release PC games, we do seem to be getting a better variety of games again.
Out of all the games I've bought in the last few years, the ones I've played the most have tended to be indie games that were a little different to the normal big budget stuff (Raccettear was massive fun*, Orcs Must Die, Terreria, SPAZ etc). I think I logged 100 hours on Terreria whilst under the weather, and that's far more time than I've spent on virtually any game since possibly Baldurs Gate, or FF7.
It's great to see the niche gems making a comeback to the PC.
*And actually got me to buy a gamepad for the first time in 10 years.
