I'm with you, though, I have a fairly controversial opinion on FB and social media in general.
I think Facebook is just the result you get when the general public participates in online discourse. I believe the algorithms may in some cases magnify certain discussions that many deem "dangerous," but mostly, it's just that people have zero empathy when conversing online.
If you've seen Parks and Rec, the scenes from the town hall meetings are basically Facebook. You have one person complaining about some inane thing nobody cares about, another complaining about undesirable people in their neighborhood, another spouting off conspiracies, etc.
Back in the early days of the internet, most of the people participating in online discussion were nerds. This fact alone made the discourse more manageable since most forums focused on discussions around specific topics.
Of course, there was always the "General Discussion" parts of any forum which suffered similar problems to what we see on FB. The difference was, the forums were heavily moderated. I'm sure many here have stories about some authoritarian mod that banned them just for having a different opinion.
Facebook on the other hand, isn't moderated much. If you start a flame war on FB, there is no one there to ban you. In the earlier days of the internet, you would get banned pretty quickly if you veered too far from the acceptable level of discourse.
Shit, look at forums with little moderation, they are 1000x worse than FB or any social media app. There is no algorithm that made 4chan the cesspit that it is (was?).
Personally, I think FB's approach has been pretty hands-off, and I think this is the correct choice for their platform.
It seems, what everyone wants (this "whistleblower" included) is for the ideas they don't like to be moderated. The internet has shown us what "the other side" really thinks, and we don't like it.