You know, I think one can always point the proverbial finger at graphics and whatnot as an answer as to why today's RPGs can't be as in-depth as the old school ones. In the old days you simply didn't have as much pretty sparkles to make, so you could sink that time into writing a complex story and whatnot. These days a game is expected to look good and BE good. A pretty tall order to most development teams. So yeah, I'd say if everyone is willing to take a hit in the graphical/programming/gameplay/cool shit we get to do that's NOT related to the story department, then sure! Bring on that deep, complex, supposedly really really good story!
But is it really all that good? Is shades of gray really all that awesome? Is the problem really that there are good guys and bad guys, or is the problem that NONE of the characters, good or bad, are fleshed out enough? Is the problem really the conflict, or just the design of the characters? Take Thane Krios, to name a fan favorite...
Here's a man who is supposedly one of if not THE deadliest assassin in the galaxy. Groovy. We get a few cuts of him doing his thing and sure, you get the idea as to what he can do. But then we learn more about him, and his son, and the spirituality thing and the fact that he has the capacity to be a cold-blooded murderer (no pun intended) basically doesn't even show up again. It's not that Thane is a good guy, or that the Collectors are bad or whatever, it's just that they focused too much on Thane's sensitive side to make him a character you can root for/feel sorry for. All things in moderation, he could have been a bit more cold, a bit more callous when it's business-time. We could have been reminded on occasion that in addition to being a pained father and a dead man walking, he's also a natural-born killing machine.
I've seen alot of gray in my entertainment. I took to some of the franchises and things that I do because I got SICK of all the gray. The world is shades of gray, isn't that enough? Why does my entertainment have to be such all the time too? Again, all things in moderation. A double-agent or a morally ambiguous person, elements of the infamous gray, do not make up for poorly-designed or poorly-used characters. I like what Bioware's done. With all the Fallout-esque games out there showing our future as a burned-out, nuked-up mudball of savages, it's nice to see a positive vision of the future once in awhile.
So no, I don't think Bioware really needs to grow up, so much as they need to learn to use their tools and parts and props and pieces properly and to their best extent. Fans and other people should also learn that while gritty gray can be and sometimes is good, it need not and should not be everything we do and see. We get enough of it in real life, do we REALLY need more in our entertainment?