To me, when the "a boy must look like his father" excuse for a father having his son circumcised is used, it seems like the father is actually doing it for his own selfish reasons. It seems like the father just doesn't want his son to have something that he could never have, and he doesn't want to be reminded of what he can never have.

Also, people tend to hate what they can never have, and a lot of circumcised guys shame uncircumcised guys for having foreskins.