[jacobolus]

Feynman was complaining about something different. He was in the middle of working on large-scale projects and got annoyed that his coworkers got completely distracted by irrelevant (but amusing) tangents instead of doing their next task that everyone else was blocking on.

This is a problem of the coworker’s lack of executive planning / control / time management skills, not anything about learning via projects or theorizing. Arguably if the coworker had done a bit more project-based learning he would have better practiced those skills.