Well at least according to the article, there was a very clear direct correlation with the artificial stuff. Based on the quotes in the article, it seems like most believe it's something to do with the composition of the engineered stone itself, but it could plausibly just be it's so cheap it makes installation more common. Either way, the reasoning of "there is a very clear correlation between the popularity of this material and this debilitating disease, and regulation doesn't seem to be working, so let's just phase it out" seems like sound reasoning to me.