Because "delicate ego" leads to behavior that evokes more ego bruising from others.

See, "delicate ego" cannot be toughened up with a good beating. "Delicate ego" gets more delicate as time goes on, but never gets beaten to death, oddly.

I guess you need to pick ego up by the shoulders, brush him off and say, "hey, let's stop bringing on these beatings, eh? there ya go, champ. who knows, the other feller might'a had a good point."