The majority of me agrees with his viewpoint but I do not find it to be copyright infringement and I do not see it as a bad exercise.
- not really a fan fiction “market” per se - not typically a money-making venture, but more a hobby
- I do not see how any bit of creation, even if derivative, is a bad exercise (though I can certainly see a bad result when it ends in one) I suppose it could develop into a crutch, but someone who this happens to may not really be cut out to be a professional writer anyhow.
I avoid fan fiction like the plague. But a derivative work CAN be original and interesting, I will never say that is impossible. The Star Wars EU is essentially professionally-made fan fiction. A lot of that is very very good.
I think GRRM is being overzealous, honestly. I normally can’t fault this man for anything - also I can fault almost any fan fiction for everything. Initially, I read that he was strongly opposed to fan fiction and thought “That GRRM, again! Always perfection.” Then I read the reasoning and was a slight bit put off.
I typically hate fan fiction because (when convenient to the fan author’s whim or personal taste) it completely ignores characterization and universe. The fact it does this, for me, calls into question whether or not the person truly likes the original work due to most likely having completely ignored what it was actually about.
I really don’t care much about copyrights.