There is a lot of people, of which I was a part of, that claim Tolkien is too much boring, cookie cutter and bed time story. That there is no gray to him and the stories never feel "dark" or serious, that they are too high fantasy. Now personally I have a "hypothesis" to explain some of it(in short: Dilution), but that's for another thread.
Now cause I was an idiot, I had some selective amnesia about the LoTR trilogy. But then I read the fucking Silmarillion and the Childreen of Hurin...
P.S. I do not believe that Tolkien is a perfect writer, but I hate unfounded criticism.