In a capitalistic system, companies come up with strategies that target the most lucrative market. It just so happens that, now, the mature market is the one where the big bucks are.
If I remember correctly, the majority of gamers are adults, and thus kids make up naught but a minority of the total market.
Also, I highly doubt that most games are M. There's probably a plethora of games that are great for kids but don't get as much advertising and media buzz since adults won't play them as much.
You have yet to even cite any figures and are could, in all reality, just be making an argument against an idea that is plain wrong in the first place. I advise that you do some minimal research and use that data to extrapolate a worth while idea rather than just making passive observations and making a large generalization, very likely 100% wrong, and ranting on about that incorrect generalization.
I didn't mean that most games are M, I meant that most of the really fleshed-out ones I can find are. Sorry for that bit of confusion. See, I want to play games that have lots of cool features and massive worlds and stuff, but that don't have the nasty content that IMO is ruining society. However, most games I can find that do not have said content, are cheaply-made due to the gaming companies targeting the mature audience. There probably are some games out there that have a good amount of content while staying appropriate, but they're surrounded by so many mediocre titles that without any media attention it's VERY difficult to find any of them. It's like the difference between searching for "games like Pokémon" on Google, vs searching for example "Digimon". Searching the former would get you so many trash titles you'd probably never find anything good. Searching the latter would get you an actually-decent set of games, with very few trash titles mixed in with them. However, what if you'd never even HEARD of Digimon? Then you'd be stuck at an impasse. As I am now with trying to find something new to play.