Warriors have been theorycrafted extensively for many years now. When a change comes out, its pretty easy to dissect that change and get results in a few days.
When Bears and Pallies started tanking extensively in BC, the amount of people looking for information on them far outweighed the amount looking for Warrior info (even though we had gone through a major overhaul too). That settled down too towards the end of BC.
DKs are still very much in the test tube phase. While they have been studied pretty hard, there isn't a lot of time tested data to go on, not to mention that Blizzard has been trying to "balance" them pretty proactively and there is a major change virtually every patch.
Once Blizzard kind of gets set on what a DK should be baseline and people are able to build on previous theorycrafting as opposed to having to overhaul everything each patch, you'll see less and less of the DK "omg whats my rotation" kind of stuff and more of "hey, I just thought of putting these 2 points differently in my spec, what would be the TPS change?" post.
60% of the time, I work all the time...