It is implausible that people have noticed that serving "Christians" and "African Americans" content they want to click on is profitable, but nobody has put the data together to realize that they can do the same thing to "Liberals" and other favored groups here on HN.
It's just, those articles won't get upvoted and clicked on here. Nobody wants to talk about themselves or their favored groups getting targeted like this.
There's plenty of people here reading this and congratulating themselves on how they aren't stupid like those groups, and then rolling straight over to their own content-farmed, clickbaited news solely posted for ad revenue that fits their own ideology one browser tab over.
"Those groups are the stupids! Not like imtelligent youse!" is one of the perennial clickbait stories. It's part of the reason why clickbait is so dangerous; a certain amount of division is inevitable, but people deliberately deepening the divisions just to make .0001 cents per view is not!
Touché.
It's also interesting that these are the groups that have been identified as the best targets for a propaganda campaign. (Edit: You would think this would be successful for a wide variety of groups across the political and social spectrum.)