I would say one has simply not really looked around to notice the more mature adult RPGs on the market. MegaTen comes to mind. Persona 3 and 4 can't even be bought by teenagers in most countries, and while their stories are set in Japanese High Schools, their themes and stories are for an older audience. Hell, even Final Fantasy crosses over into adult themes. Take the train-wreck that was XIII, it's core story revolves around characters trying to come to terms with their imminent deaths, not something a teenager really contemplates. Hell the game's most loved character also happens to be the oldest (well mentally) and a father. Games like Suikoden dealt with politics, Breath of Fire dealt with religion and probably one of the most poignant dystopias I've ever seen in a game. I would argue that adult themed JRPGs don't exist because no one has interest but rather that RPGs lost their niche (the story based game) and the last decade of trying to find a new identity for themselves hasn't been going very well. Yet they have been making adult themed rpgs from a subject matter point of view. I mean look at anything Tetsuya Takahashi has directed... The amusing thing here is that RPGs started to go down hill once these series got retired and the market started to get overrun with the tween heavy rpg series has the genre began to really go down hill. If RPGs are going out of style because adult gamers don't care for them, doesn't that really say that developers have failed to make the game for the right demographic as opposed to the genre being inherently meant for a different target group. I mean kids games still sell well in the gaming industry, so if JRPGs are losing ground, it's because they don't appeal to anyone.

The issue with FF is that Kitase himself believes that older fans should give up on the series and let the younger people enjoy it instead. He pretty much said he plans to keep writing only for the teens/young adults despite the fact that Squenix's biggest game successes are adult oriented titles from Eidos, or remakes/ports/sequels/spin-offs of older FF games. The two biggest games on the PSP from SE is Crisis Core and Dissidia, two titles that are blatantly targeted for a part of the fanbase that is old enough to know what the hell they are. I think if SE actually made a more mature FF, they would find that part of the problem with JRPGs in the modern age is that JRPG developers don't know their audience as well as they think.