> At its best, I guess you could say Facebook helps you kinda-sorta keep in touch with old friends you don't see that often.
It's more than that. At its best (your phrase) FB helps marginalized people or those in rare circumstances (e.g. health-related) find others with similar experiences who can offer advice and support. It has helped people reach out to one another during emergencies. Yes, those are extreme cases, but you used the phrase "at its best" so let's not understate what the best is.
> somehow suspect that's not what the majority of FB engineers are actually working on.
Of course it isn't. Like at every other tech company, the engineers are mostly working on their own piece of technical infrastructure. They're not directly out there saving lives. Nor are they directly out there ruining any. Is it fair or useful to blame individuals at Facebook for the worst of what their company does, and simultaneously deny them any credit for the best, with no idea what role they actually play or what direction they're trying to push the company in?
Does anyone here suppose that oppressive governments around the world aren't also using RHEL and Hadoop to target their victims? Dell servers? Cisco switches? Who provides their cars, their guns, their bone saws? There are many companies at least as complicit in all of these awful acts, so why is the tsunami of self-righteousness only directed at one? Are people motivated by a desire for justice, or a desire for the approbation of others? Dopamine addiction isn't limited to Facebook users.