This is probably stating the obvious, but most people watch television to be "entertained." They don't sit and think about the plot. They don't wonder about the character's motivations. They just passively watch. Producers probably know this and don't feel the need to spend extra money to appease a small portion of the population, even if it would make the show better all-around. They have no incentive to make better characters.
No, this isn't stating the obvious, it's cheap, unthinking cynicism. In reality, TV shows compete against each other very aggressively, and having more complex, interesting, realistic characters can and does bring a huge competitive advantage to one show over another. That depends on the genre, in the more lowbrow sitcoms you may want a very stereotypical character instead, but those do not capture all the market or even most of it. What you're saying is easily falsified just by reading a few articles on which shows get cancelled and speculations as to why...
From EY's Facebook page, there were two posts that got me thinking about fiction and how to work it better and make it stronger:
I was wondering if we could apply this process to older fiction, Great Literature that is historically praised, and excellent by its own time's standards, but which, if published by a modern author, would seem substandard or inappropriate in one way or another.
Given our community's propensity for challenging sacred cows, and the unique tool-set available to us, I am sure we could take some great works of the past and turn them into awesome works of the present.
Of course, it doesn't have to be a laboratory where we rewrite the whole damn things. Just proprely-grounded suggestions on how to improve this or that work would be great.
P.S. This post is itself a work in progress, and will update and improve as comments come. It's been a long time since I've last posted on LW, so advice is quite welcome. Our work is never over.
EDIT: Well, I like that this thread has turned out so lively, but I've got finals to prepare for and I can't afford to keep participating in the discussion to my satisfaction. I'll be back in July, and apologize in advance for being such a poor OP. That said, cheers!