"I just like the idea of my escapism actually feeling less oppressive than my real life again."
That mostly sums up the point of Will 2010 Be The Year Of Superheroic Niceness?, an accurate piece about The Big Two's plans to turn their lines lighter, less grim (marketing hooks are Heroic Age at Marvel and Brightest Day at DC). Though the piece avoids laying any blame on the actual comic writers that's really where it goes (and I'm including the editorial staff here since in this world they're far more a creative force than book publishing editors). They're the ones who seem incapable of moving beyond the status quo and whose collective idea of "serious" is determining which character dies next. So we get a constant stream of Big Events where Nothing Will Ever Be the Same (though it always is), heavy-handed preaching (do good, people) and sheer jaw-dropping stupidity (not the fun kind either). Just so we know that the creators are serious.
Some of this is almost built into the system. Since each company has to produce a significant number of issues each year, most featuring tentpole characters, after a while it's hard to keep that interesting. So there have to be changes though usually not ones that will alienate the readers (though the widely disparaged Kyle Rayner and One More Day events show that no matter how much fans complain they won't completely abandon characters). This is where the grim 'n' gritty comes in. Ever since the double-whammy of Watchmen and Dark Knight Returns most comics creators have assumed that what gave those works their power was the violence and sex and took them as a license to go wild until we end up with the traditionally light DC giving us a teenaged girl tortured to death with power tools (though she got better) or another stuffed into a refrigerator. Or over at Marvel the entire Ultimatum mess.
Admittedly those are extreme examples but the general feel has been that comics creators think they have to engage with The Real World though the results are rarely worth the trouble. These are after all stories about grown people in colorful, tight costumes and boasting magical powers - there are limits to realism before they just become silly. (One of the nadirs is the Iron Man movie when in blatant Bush propaganda he trots over to the "Middle East" to vanquish the bad guys, though almost anything Judd Winick writes is also a good candidate.)
So in a way to move from the kids stigma that always haunts comics, many creators push to be more grown-up though apparently without really understanding what that might mean in this context. Just look at Identity Crisis which took a "real" novelist for writer and gave us a stupendously misjudged moment with the entire rape sequence. (The tiny footprints on a victim's brain was also misjudged but in an entirely different way.) This isn't the place to discuss why murder is acceptable for pure escapist entertainment (just turn on your TV or see the walls in libraries & bookstores) but not rape, or at least not in Anglo-American culture. In fact it's a little hard to imagine what the creators were thinking but the clear point is to, y'know, keep it real and apparently rape, murder and forced lobotomies are the only ways they could think to do that. Just recently in the Blackest Night event Kyle Rayner died and the forums were full of comments about how successfully DC managed to keep this quiet. The reason as it turns out is that he was resurrected the very next issue with The Power of Love just like T'Challa in the current Black Panther series. (And as much as I defend superhero comics it's stuff like this made by adults in all apparent seriousness that make me want to jump ship.) On a broader level that's why we're also getting this constant stream of dead characters or why potentially substantial stories such as Civil War end up being yet more one-sided blather - the creators are so blinded by an idea of "reality" that they can't think of anything else to do. (It's also why so many stories take five issues when one would really be enough - they want to tell every little moment.)
I'm not saying that we should go back to the Silver Age - that ship has, as they say, sailed. But it's notable that the kids comics released as Marvel Adventures and Johnny DC (most apparently cancelled now) have been more imaginative, substantial and plain fun than the regular series. And there are some that can be considered "grown-up" without falling into this grimness trap - at the moment I'd point out Brubaker's Captain America as an example even if he did kill off the main character. Perhaps this is in some way related to the constant need to point out a moral that tends to infect so much mainstream comics (though it's possibly even more prominent in TV). The creators don't entirely understand how to tell a story or at least don't feel comfortable if that's all they're doing.
I'm not suggesting that comic writers need to bone up on Henry James or Chekhov but certainly they appear to have read too narrowly. Geoff Johns is a perfect example of somebody intimately familiar with comics (at least superhero comics) but seems to have little beyond that. Just check out his recent Green Lantern run for an example of how turgid and insular a writer can get. It's enough to drive a reader over to Ware and Tomine and etc. Honestly though I don't expect anything to change. There's still going to be some good work done amidst the flow of junk and while some people will claim that's always the case for anything I can't help but keep hoping otherwise.