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.
"Yes, we sold our previous 2 businesses. But I want to point out that (1) neither of those sales ever hurt (and arguably both sales greatly helped) our users, (2) Keybase deserves special consideration which we are aware of, and (3) both Max and I are happy in a world where we never try to sell a company again, and only build things we like."
I feel silly for falling for it too. Even very wealthy people enjoy extra money.
