I think a bigger indicator of death is when a company neglects problems, or lies about them. Facebook has not denied problems, which makes me think they might fix them.
I had problems with facebook since 2005ish, and actually creating a rival to facebook was a big motivator for me to learn to code, but now I've since taken up my own interests, and am not so concerned with facebook, since I see it, in some ways, as a necessary evil. (though I would rather see some sort of decentralized blockchain thingy that serves as the global directory of connecting all people)
Also, if you are in the valley, you are posh and already "over facebook", you are an early adopter of a facebook-less world, and you don't realize how obsessed with facebook people are in the midwest(where I am). I'm not saying a facebook-less world won't catch on here, but where I am, people aren't anti-facebook at all.