aristotle - 1:02 pm on Jul 4, 2013 (gmt 0)
It really doesn't matter whether Google can measure quality or not, because it's only a very minor factor in their current ranking system. They had to de-emphasize it because it was preventing them from getting big brands and big organizations to the top of their search results.
You say the above as a very definite statement - but I think this may be just your opinion rather than stating the fact?
Well it seems like an obvious conclusion to me. Do you have a better explanation for why Google's search results have deteriorated so badly over the past few years?