A civilization reaching the stage of the computational revolution stands on the event horizon of a Singularity; some cultures call it Ascendancy. What it matters is that once that stage is reached, they may disappear altogether, for reasons unknowable to pre-ascended minds.

Likewise, the leaderboard only contains pre-ascended individuals (Paul Graham has a higher karma, but is not listed). From the listing we may assume the ascendancy limit lies somewhere in the vicinity of 50K karma.