I used to feel very strongly about these things too, but ultimately I think everybody is up to build and pursue whatever they like. We can't force other people to do things our way. We can attempt to persuade them to, or guilt-trip them to, but we can't force them to care about what we care about.

That said, humans have always have had "odd" priorities that might not make sense from the lens of rational cost-benefit analysis. Venkat Rao wrote quite an interesting piece about this- about how some people genuinely prefer the occasional escapism of movies to, say, proper sanitation.

We don't sit down and rationally work on our worst problems, we're aspirational, we're idealistic. People working on humanitarian projects have found that the threat of death and the promise of salvation from death DON'T actually stop people from defecating in the streets, etc.

It may be that people want Facebook more than they want protection from violence. That might seem utterly crazy, but it might also be true. That said, Facebook is free to do as it pleases. C'est la vie.