The nicer you state your messages the more people will listen to you.
The meaner messages you can stomach the more information is accessible to you.
So we'd expect those who demand others to be nice to be less well informed than those who can tolerate mean communication. For example, a person who thinks their math teacher is mean when the teacher corrects them will probably never become great at math. I believe that this is an aspect of communication we need to talk way more about, since large parts of the population are currently handicapped like this.
I'm not sure if it is genetic, but if it can be taught then we ought to tell our kids to listen to everyone and not just what feels comfortable. Fill your kids heads with statements like "It was a bit mean, but he is right, you should really try to do FOO". People often have good reasons for being mean, they could be tired, hungry, depressed or just spoke without thinking, those are really bad reasons for not listening if the actual message is sound.