I disagree with the premise. Very few people fear rejection. Everyone in some way has been rejected thousands of times by society. Everyone has had their resumes tossed in shredders. And their hearts thrown in the trash.

No, what they fear is shame. Not meeting the standard that you or society has placed on yourself.

For example, no one would mind getting rejected by a celebrity/social media star, but they would mind if they were rejected by a friend.