Quote from Monstar Maalik
but manga's with that target audience aren't going to have deep and intricate plots, it's just like he said, the naruto's and d-gray mans and whatever the popular shoujo's are for that age group are....
Sorry, have you actually READ D.Gray-Man? That has a deeper and more intricate plot than most seinen/josei I've read. You must have meant "Narutos and Bleaches", which are pretty superficial.
And that's my point: just because something is 'mature' doesn't mean it's better. There are plenty of good shounen/shoujo manga with interesting and complex plots and plenty of seinen/josei that are just plain crap. If someone has never branched out into reading other genres, okay, it's a good thing to try that, but I think it's a bit of wishful thinking to assume that'll solve their problem.
I stopped reading (most) manga a few months back because I too found most series in ALL genres boring, so I sort of understand the threadstarter's feelings. I also agree; there are fewer 'great' series nowadays, or so it seems. Whenever you see a recommendation or ranking thread, the same series keep popping up, and few of them began very recently.
That's not to say that all manga is crap now, but what a discouraged person might just need is a break.