I think people are not understanding something here.
Sales are FACTS (well, sales figures aren't 100% accurate, but within a cartain margin of error).
Quality is OPINION.
What gets nominated/wins is all down to opinion. We can't say "Oh, it shouldn't won because it sold the most". It selling well suggests people like it, but it doesn't mean the people who decide on the awards like it the best.
On the other hand, Recovery was one of the biggest hip hop albums of 2010. F-A-C-T, fact. Maybe not one of the best, but certainly one of the biggest.