Most of Zuckerberg's $13 billion net worth is based on an imaginary valuation of Facebook, apparently engineered by Goldmans. There's still plenty of opportunity for Facebook to disappear into obscurity, overshadowed by the next big thing, just like Myspace, Mixi, Friendster and Livejournal.
What you say can happen. Agree with you. My main peeve is with any such list in the first place - "actors who don't matter...", 'techie greats who don't matter' etc. etc. Makes me very angry, purely from basic human feelings POV.
And its obviously a link bait - '10 people who don't matter...' easily attracts people on to read (or just page visit) '50 people who do matter...'.
Will Facebook have lasting impact -- like you, I'm skeptical. Is Zuckerberg great on execution, and does he matter? Absolutely.
Another one (Torvalds) screams of insensitivity to the real impact created by some one. The journalist(s) deserves a whack in the back for this.
There are many people who do something noteworthy, and then fade away, for various reasons. Calling them out, in a derogatory manner is bad. 'Idiots just go away. Look at your loser self, in the mirror, when creating a list like this' I say again.