You're missing the forest for the trees. You're taking a pedantically literal view of one sentence and saying "see? it can't work!" when that interpretation of the sentence in question makes no sense at all when taken with the paper as a whole.
If you want to keep arguing that Dynamo's HH ignores the W value they spend a lot of effort explaining, fine, maybe you're right; maybe Dynamo's authors really are a bunch of idiots. Nobody outside Amazon can say for sure.
But Cassandra doesn't ignore W, and neither does any other actual system I know of: HH is just for the N - W nodes. Because that's the only way to implement it that makes sense. :)
If you want to keep arguing that Dynamo's HH ignores the W value they spend a lot of effort explaining, fine, maybe you're right; maybe Dynamo's authors really are a bunch of idiots. Nobody outside Amazon can say for sure.
But Cassandra doesn't ignore W, and neither does any other actual system I know of: HH is just for the N - W nodes. Because that's the only way to implement it that makes sense. :)