The craziest part is that these internet companies are using that stronghold to optimize for "engagement" (i.e. flamebait) that looks outwardly bland enough so as not to disrupt the "advertising friendliness" that they seek to push. "Wuhan flu" is bad because some people in Wuhan might get angry and boycott your advertisers' products. "White male cis people are all racist Trump supporters!" (which weirdly enough seems to be most often posted by a white male cis person!) is not going to cause that kind of unwanted reaction so they push it. It's pretty much institutionalized trolling, it just doesn't get acknowledged as such.