How would you know that if they aren't on regular TV. Naruto's only popular because of when it came to America and it being mainstream. Its doesn't exactly that deep of a plot compared to other shows consiering thats what it's credited for.
I want you to compare the ticket sales for George Lucas films and Wes Anderson films. Yes there's a market out there for Wes, just like there is for Oreimo or Goodbye Mr Despair. But let's face it, it's always going to be a niche market. There is a clear-cut formula to blockbuster success that is as old as time, I refer you to the work of Joseph Campbell and his book,
The Hero With a Thousand Faces:
http://moongadget.com/origins/myth.html
Campbell argued that the stories that persist and resonate with people across time or cultural borders usually shared common elements, because these comply to the universal image of a "hero". Compare the steps and elements of the hero's journey as found on the referenced page to those found in Bleach or DBZ, it's easy to do if you're familiar enough.
The Formula.
This man is following the formula.
This man... maybe not so much.
Even if the two-fisted explosion filled tales of good versus evil and hero gets the girl that are around now suddenly stopped production, new ones would emerge because those are just the stories that the majority of people want to see. It's why the end of Dragon Ball brought us three count em three of the same types of new stories at the top of the heap and still more of the same stories continue to spawn. I'm not assuming anything, the entire history of human literature is on my side.
That's not to say that less popular shows are bad, or don't have important things to say, nor to say that they can't entertain or make you think or feel. But they will never be the darlings of the masses in the way that fighting hero tales are. Your whole problem is that you think those kinds of shows are holding your favorites back from their deserved place in the limelight. I don't think that limelight could ever be theirs though. A guy like Satou for instance is just going to be harder for the average person to identify with or root for. Kids can't watch his show at all and old people probably won't care about his exploits. His show is battling both subject matter and demographic concerns. You yourself said it, Naruto is mainstream. How could you expect something without mainstream appeal to ever become mainstream?
