What happened was, A History of Violence screenwriter Josh Olson informed the internets that He Will Not Read Your Fucking Script.
Cole Abaius thought this made him a bit of an asshole, although more for the tone than the sentiment.
John Scalzi weighed in (more calmly) and agreed, although he mostly focused on the "Writers have no obligations to strangers" and "I do not owe you my time" and "I do not need to piss off people I know by asking for favors for every single stranger who approaches me" aspects.
And then David Gerrold brought up my own worst fear. See, I don't think people realize the legal jeopardy other people's unpublished work puts a working writer in. Three words for you: Marion Zimmer Bradley (fifth paragraph under "Literary Career"). If you read someone's unpublished work and you then write anything that's the least bit similar, that person could sue you for copyright infringement (i.e., plagiarism). The problem is, there are certain things, certain similarities, that are going to occur in any two works on the same subject, and the established writer may have no way of proving they did not copy. They might be able to defend themselves in court and win, if they can argue that there are more differences than similarities, or that the similarities are not strong enough, but they still have to go to court and pay those legal fees and waste that time.
Here's both sides of that, from my own experience:
When I was an eager X-Files fan in my late teens, I wrote an episode script and scraped up the courage to send it to the production office. It was immediately returned, unopened, in a second envelope with a lawyer's form letter on top, explaining the legal problems with the producers even accepting it. A few years later, there was an episode that bore two substantial, remarkable similarities to my script--but I knew they hadn't even opened the envelope; there was no way they could have stolen my ideas. If they had accepted my script--so much as opened the envelope, or just never acknowledged it, leaving no way to prove that they hadn't read it--I could have plausibly taken them to court and wasted everyone's time and money, whether I ended up losing or not--sincerely believing they had ripped me off, or at least ripped off a few key elements. As it is, I know for a fact that they couldn't have. Coincidences like that, no matter how strong, are entirely possible and no one's fault. And that's why they had to protect themselves. As John August once pointed out, if you know a show well enough to write about it, you are probably in tune with the writers enough to anticipate their own ideas. His example was a Grey's Anatomy episode a reader emailed him about--the reader was all upset because she had sent them a script called "My Favorite Mistake," and then they had an episode called "My Favorite Mistake," and did he think they might have ripped her off? And August pointed out--rather heatedly, and completely rightly--that she knew the show well enough to know that they used song titles for their episode titles, and Sheryl Crow was very much to their musical taste/demographic: "You copied them, not vice-versa. Got it?" It was a coincidence, and perhaps an inevitable one.
On the flip side of that problem, someone once emailed me her own "X-Men in Fifteen Minutes" and cheerfully informed me that I could totally put my name on it and post it as my own, I didn't have to acknowledge her at all. Unfortunately, while this might give her the illogical pleasure of seeing other people compliment it just because it had my name on it, she did not stop to consider what benefit this could possibly have for me. In fact, it not only had no benefits, it presented a bit of a problem. I was trying to get a second Fifteen Minutes book off the ground, and I had considered doing one of the two (or were there three by then?) X-Men movies. I didn't even open her attachment, but as Gerrold says of his friend, the damage was already done. If any of the jokes I thought of looked like hers--in a book I intended to publish. For money. Obviously--she could have sued me. And I would have no way of proving I did not open that attachment. I'm not saying she would. I'm saying she could. And you have no way of knowing who will or will not go after you. As Scalzi points out, a few crazy, bad, ligitious apples have ruined it for everyone else. I have no idea what your intentions are or might later be, and I have to protect myself. And so now, I would not feel comfortable writing anything about the three main X-Men movies. Honestly, I could probably put it out for free with no legal problems, but I feel a childish bit of pique that I was even put in that position. And so much time has gone by... that's probably the real reason I wouldn't write about them now, but there you are.
So what I'm saying is--bottom line--is that a writer refusing to read an unpublished work is an attempt to protect himself from possible legal consequences. Moreover, a writer refusing to read an unpublished work that you have already sent him unsolicited is not an unkindness. It is a response to an unkindness you have already done to him.
ETA: From annlarimer : What happened to Chelsea Quinn Yarbro; from dwg , Laurell K. Hamilton's take on the Olson piece.