Those who hold this view are actually in the minority I think. Most people praise him without reservation. As for how the books are somehow not bleak and hopeless, I'd love to hear you explain that. Personally, what turned me off from the series was reading the prologue to Game of Thrones. I thought the Others/White Walkers were really cool. I was wondering how the humans would manage to defeat them and was going to get the book to find out more. Then I found out that they never appear again, the books are mostly about politics, and everybody dies. -_- I feel lied to.
They do appear again and not "everyone" dies. You've got characters alive who can still prevail in the end, and I think that satisfies the definition of "hope" quite well.