It's up there because it's probably the most OWNED album, seeing this is DTF and all. Probably 4 times as many people own (or downloaded) that album compared to say, Agalloch, which is hight because a few people rated it very high.
Something similar with Intronaut - 2/3rd of the points come from Sigz and I. It's a hell of an album, but very few people here have checked it out so its going to languish.
It's far from a perfect system, but people are limited to what they are exposed to, and it makes sense that more people own that album since this is DTF. It's racking up a lot of 6-10 places, and all those little bits add up.