Unless I imagined it, they previously said publicly that they were unlikely to pursue a sell like this because they had succeeded at previous companies and cared more about the impact this product could make than the profit they could make from selling it. I based my decision to agree to the terms of Keybase around this statement which I can conveniently no longer find. I suspect it was in one of their airdrop announcements, and conveniently those links don't work in the Wayback Machine.