Beginning to see the light. Still no self awareness.
Academic lawyers do a fair bit of pontificating too, though not nearly as much as the academic philosophers, and theirs is almost always confined to real politics. The really revolting aspect of some academic philosopher behavior on FB is its "high school with tenure" quality: back-stabbing, preening and posturing, endless displays of righteousness and "pearl clutching", faux solidarity with all the oppressed and "wretched of the academy" (less often the actual wretched of the earth), and so on. An awful lot of academic philosophers on FB come across as teenagers desperately seeking approval and affirmation. I've managed to "unfriend" most of the offenders, but it was really a kind of depressing and sickening spectacle while it lasted.
Why don't academic lawyers on FB engage in this kind of tawdry behavior? Academic lawyers, having gone to professional school and often worked as professionals in practice, may just be more mature as a group (though I also suspect there is a selection effect at work, i.e., those academic philosophers most prone to this behavior are drawn to FB). But another part of the explanation, I suspect, is that academic philosophers are more powerless than academic lawyers: many of the latter are actively engaged in policy work, law reform, and litigation on the issues they care about. All academic philosophers can do is posture and preen on FB.
But what's really interesting is how different the actual lawyers on FB are: there's none of the tawdry displays of virtue and righteousness, and there's hardly any of the pontificating. The explanation there is, I think, pretty simple: they are way too busy to indulge themselves this way. The same goes for most of the other regular people I'm friends with on FB. FB, alas, seems to be evidence that academics do have way too much time on their hands.