I guess he doesn't considers people who have a hard time interviewing as "excellent" as he said.

Sorry, I meant "interviewing" from the perspective of the interviewer. Reliably selecting good people to join your company is often thought of as a difficult task.

He's trying an analogous evaluation of the founder - and giving it more weight than the paper plan. Possibly quite reasonably, but it seems the success of the approach relies heavily on something people seem to find difficult.