I mostly meant the investors. They need a few very definitive outcomes which tend to happen slowly (although there are probably signs the outcome is happening). Startups want those outcomes, but aren't diversified enough that they're expected to get one. That's my sense at least.

To put it another way, great founders can fail by making one bad decision. Great investors often succeed by making one really good decision every few years. So for a long time, a soon-to-be great investor will mostly look like a failure.