I think you're missing my point. I'm not saying that Facebook should give up. Everyone there should make every effort to improve. My point in bringing up complexity is that it's going to take a lot more than Mark waving his hand and magically making everything better. This isn't some video game where one player hits a button and thousands of minions instantly rearrange themselves and all of their actions are resolved in milliseconds. Anyone who knows anything about complex systems - especially those involving people - knows that's not how they are.
In reality, no matter what leadership says or does, actual change will still require continuous effort from literally thousands of engineers, data scientists, and others. It will take time, as all such things do. Petulantly demanding that things happen faster than they can happen isn't going to make it so.
That's really an argument someone is prepared to make.
One role a CEO can play is to direct a company to act in particular ways.
The responsibility for anything Facebook does or doesn't do absolutely lands squarely on the companies leadership.
Saying something like: 'welp, it's too complicated to understand, but fuck me look at all this money and power...
Isn't going to convince me.