Overt self exaltation is seldom taken serious. Who cares if someone wears a shirt that says "world's greatest dad." Such statments are mostly deemed silly, and usually uttered as an obvious absurdity for the sake of humor. The real problem is the covert self-exaltation. It is like a spider web ... you may not see it coming but once you walk through it, it is hard to remove .. and it just feels iky.
Let all forgiven be rewarded equally to their forgiveness which is equal. Let all evil, that remains evil unrepented, be punished equally to evil's deeds. ~ God [Letters from God and His Christ - Volume 2 ~ God is Sovereign]