I think it's actually that individuals with high levels of academic success don't need to start a company, they already have very good high paying career options. And so starting a company has a high level of opportunity cost.
There seems to be anecdotal evidence. I've read about and talked to founders who have said things like "They just could't get hired" or "couldn't handle working for someone else" and "had no other option but to start their own business".
that said - very likely a survivor bias in those samples..