Hype List
Tomorrow's great artist, politician, or business man may only be influenced by a couple of people who many may never know.
And that's the real influence (which you can't put on a list).
Like the list of the most influential Hollywood players by one of the Hollywood magazines, it's more a hype list, a list of the flavor of the year.
In this context, Issacson can be on the list, as he's Steve Job's biographer, very much shaping the way Jobs is seen (I'm curious on a non-authorized biography, which we'll see much later than Isaacson's work, as this would take much more research).