The term social media as applied to Facebook (and the like) is a misnomer anymore. It has become a business/marketing tool. The focus has shifted from its nascent days implication of serving a social good to a strictly revenue generating proposition. This was the result of monetizing it, which inevitably treats people like a commodity.
Whereas a real social mission seeks to transcend fragmentation by serving a common societal good, the latter is a quest to filter the greater common good into increasingly smaller and discrete niche communities for targeted advertising that caters to individual tastes and preferences. As such, it concentrates on the multiple divisions of differences or differentiating factors rather than commonalities. Arguably good marketing…but bad social policy.
This also has exposed the worrisome side of teaching multiculturalism in our schools, insofar as it too has us focusing on our differences and what makes us incompatible in light of these differences — even though it originally aimed to breed tolerance for these differences.
Unlike assimilation or cultural pluralism, both of which preceded multiculturalism and conceptually focus on the common ground of country first, we are now a salad bowl country — to wit: we are all different and just happen to live within the same national borders. The very ideal of country — and country first — has been greatly discounted by this notion.
Social media like Facebook amplify the presence of this unintended consequence by making it ever easier to focus on our differences. Moreover, it takes this a step further by helping to normalize the fostering of a distaste for those unlike the “us” in a market niche segment (precisely because Facebook, as a social media context, connotes cultural implications too). There’s no checks and balances for curbing this divisive activity. And as you aptly state, curbing it would be counterproductive to achieving the profit motive of Facebook.
It’s not social media, and framing it as such should be stopped because it’s deceptive, technically wrong and unfortunately harmful. It’s simply an ad agency, and it’s in it for the money.