Thanks for the link, I watched it for myself and wrote a fuller transcript.

  Q: If a young developer said they wanted to fork SQLite and build something better, what would you tell them?

  A: ... lots of people have tried. You're welcome to try. I think that the time has passed; it takes twenty five years, and it takes maniacal devotion to the cause.

This transcript doesn't include the hesitation, pauses, repeated words, incredulity etc. I got the vibe of beware wasted effort not an enthusiastic go do it quip.