Americans have a habit of doing any damn thing they want, often disregarding the others' feelings/opinions. This is not a Japanese trait - much the opposite. That's why it doesn't make sense..."it's just a logo" attitude cheapens & dismisses the heritage & ansestors that built the family/clan. You, as potential mon-usurpers don't need to understand all the intricacies, just that it's not proper & to respect the cultural value.
Although I am sure you meant as little harm from this statement as possible, I still am rather offended. And I won't go into any back and forth bickering, but every culture as their bad apples; and as your encounter with Americans may have been unfortunate there is still a sense of honor in most Americans today. So, please, keep what you say impersonal.
Saya no uchi de katsu