Yoga Pants: The Downfall Of Denim?

If you believe the news, the decline in Jeans sales (6%) is directly attributed to the fashion trend of more comfortable and less-pricey yoga pants.  Now I disagree with the experts who say Jeans are forever on the way out (after all, the denim mine on Levi's Mountain is forever in my mind), but I did wonder if there was any truth to the increase of Yoga pants into the workplace.  My unofficial results:  I had trouble locating the "yoga pants in the workplace" craze.  There were two workplace environments where my quick search of the interweb located yoga pants replacing denim.  The car wash, and the on-the-street  reporter.  I have enclosed these photos to give my argument validity.

For the sake of equality, I thought I might include a few denim photos simply for comparison.  I have no idea which is more popular based on my research.  Perhaps more field study is required.