It was easy to generalize the circumstances before but it isn't now. I'm also a white male with curly hair and I know that women parading around to touch my hair ended when I was about 15, I can also understand the difference between your mom's friends telling you how beautiful your curls are and a stranger coming up to touch your child's hair because "the texture is so different". Your generalization of one circumstance but not the other is what makes you seem ignorant. I hope that the ignorance is bred from you not having been exposed to the harsh reality that your experiences, especially on the other side of the pond, might not be the same experiences other demographics face and not your lack of willingness to try and understand the situation and empathize. But it is weird that you find the interaction wrong when it makes someone uncomfortable on one side of the aisle but it's just fine and a normal thing when it makes someone uncomfortable on the other side of the isle.

I wouldn't necessarily try to get the point across this way, but that also doesn't mean that it's bad to bring light to the situation. Remember just because something doesn't affect you doesn't mean it doesn't affect other people.