Beating people up for not having your morals is not a great way to get them on your side.
Facebook has been on my list of companies not to work at for a long time, but I have friends who work there. Accepting that other people value different things and being willing to interact with them on a basic, human level is a lot more likely to build bridges and lead to constructive conversation about important matters down the road than casting people aside because they don't conform to your worldview today.
I'll grant you that Facebook, among others, enables exactly the sort of thing I'm advocating against. I'll grant you that it seems to promote people yelling at each other over the internet instead of building the relationships that enable difficult conversations in time. And I'll grant you that they do it to sell ads for shit we mostly don't need.
But that doesn't make everybody who works there bad, and it doesn't mean that people who decide that continuing to work there is no longer consistent with their values should be equated with merchants of death when they publicly leave.
You're castigating somebody for voting with their feet, but presumably mostly because they didn't do it as soon as you did.