I don't know that editors wouldn't like Tolkien's writing- but being concerned with the bottom line, they might not publish it. But that was a concern back in the day, when (forget the name of the publisher) thought he would lose a thousand pounds, and still published it. His writing style is plodding, but still better than most of what does make it past the editor's desk.
The only fantasy writer I've read that I think outshines Tolkien (in writing ability) is Peter Beagle. He had a wonderful command of imagery and metaphor. Tolkien I admire for being able to write in an older style without sounding affected.
Martin's writing is good, but on the whole, there is something about Westeros that makes it feel like a great miniature of a world, rather than a giant, sprawling world. I don't know exactly why this is, but it is perhaps that so much high drama is always happening and everything is shown to tie into itself. It is a bit like a bonsai tree- it's all there, but slightly distorted. I chalk it up to his past as a television writer. As for body count, it really isn't that high, as far as main characters go, but they do get thrown through the angst mill too much. Martin's writing is intricate and mostly believable, but Tolkien captures a sort of elusive depth that no one else seems to have.