Strictly speaking it wasn't his, it was the originator of that thread, jgarzik, and satoshi replied "We can phase in a change later if we get closer to needing it.", which doesn't strike me as a ringing endorsement.
At any rate, the suggestion was for one increase, not an infinite sequence of increases, which your suggested exponential growth amounts to.
At any rate, the suggestion was for one increase, not an infinite sequence of increases, which your suggested exponential growth amounts to.