Can you expand on the message please? :-) As I read it now, saying "some of them" makes this nearly a tautology.

I have been on the well-rounded side (and have learned some pros and cons of the same the hard way), so am additionally curious to hear. :-)

I get the impression Thiel really means "most if not all of them," but I didn't want to misrepresent.

When he says "well rounded," he means kids who participate in a glut of extracurricular activities to pad college applications and create many possible career paths for themselves.

The argument being that with many potential paths, people tend not to commit to any particular future vision, which results in fewer people with the concentration or desire to build those futures. Elon Musk is presented as a counter-example.