Come on, of course it's because black market stuff is sensational. Even if analytics prove "black market stuff" actually doesn't prefer BTC (as Lucius shares 2 posts above), you'll still write otherwise.
It's a business model that's built to extract the most value out of anything that makes people click.
I however find that people should be able to post whatever they consider a worthy read, no matter how non-worthy others might find these articles. If you don't like an article, then ignore it and move to something that does interest you.
I find the discussions these articles spark quite worthy to read on their own, and it also shows how people here think about this subject and how their opinion has changed or not changed throughout the more recent years.