He's ridiculously slow, and I definitely think that as a professional author he should be capable of getting his books out at a quicker rate than this. Other authors do it, and his writing isn't such a godsend that it should need so many extra years compared to other authors.

That said, it's his book and his series, and his only obligations are meeting the demands of his publisher and meeting his personal monetary needs, for which he publishes books. And possibly his artistic demands, to get everything perfect, etc. My point is that the readers don't exactly matter to him. We're not in any sort of deal with him, he doesn't owe us anything. We benefit from his hard work, and pay a small fee for that benefit. But we pay for the single book, not the continuation of the story, so he owes us nothing.

So I think he has every right to publish at whatever pace he chooses... Provided his publisher lets him get away with it. I would certainly want him to waste less time, to not occupy himself with twenty other projects when this should be his main project, and the one he busies himself with the most. But that's ultimately his business, and while it makes me dislike him as a person, I still love his books and will continue buying them. And as others have said, there's plenty other things to read and do in the meantime...