Why? Do you not think it's quite normal to be angered by another person adopting a cultural element that is distinct to your background, but without an understanding of its broader socio-cultural context and significance? Do you not think there can be justifiable antipathy towards the notion of distilling a subjugated culture and its iconography down to fashion and trends?
People self-identify with all sorts of things and then take offense at any perceived slight to them. It's commonplace human behavior based on the psychological sense of the self or "ego".
I once knew a woman who self-identified with the brand of cigarettes she smoked. In her eyes, to criticize the brand was to criticize her, and she could be reduced to tears simply by remarking something to the effect that they tasted bad. Whether it's a brand of cigarettes or an object of traditional sacred significance within one's culture, the fact that someone takes umbrage at its "misuse" or "abuse" by another person does not in itself in any way necessarily impose a burden on the person "giving offense" to cease giving offense. We are in no way obligated or required to be the guardian of another person's ego. We may do so if we are sensitive to, and considerate of, someone's self-identification with an particular object, but we are not obliged or required to do so.
The issue here is in some ways similar to the issue of free speech. Do you or do you not have a right to speak your mind on a subject if and when speaking your mind gives offense to another? Are you entailed by their offense to cease speaking your mind? Even if your speech is rude and obnoxious, are you entailed to cease speaking your mind? By imperfect analogy, if you take something from another culture -- even if that thing is of sacred value to the people of that culture -- and you use it in a manner that devalues it in their eyes, that gives offense to them, are you entailed by their offense to cease using it in that manner? Even if your use of "their" object is rude and obnoxious to them, are you entailed to cease using it in that manner?
I am not arguing here that it is never, say, vulgar or even obnoxious to use something culturally significant to other people in a manner that those people take offense at, but I am seriously questioning the notion that those other people have a right to determine how everyone uses things from their culture based on whether certain uses or "misuses" gives them offense.