Being Hispanic I can say that I wear my rosary not for fashion reasons but because I have been raised to have a great respect for Our Blessed Mother and the rosary.
That some would use it as a gang symbol is between them and God, not because of culture but from ignorance. I think to say across the board that all Hispanics wear the rosary for fashion reasons or national identity is try to put in a box of opinion and not fact, an entire ethnic group, which I find disrespectful.
I have no problem with anyone wearing the rosary, just as I wouldn’t have a problem with someone wearing a chain that has a cross on it. If you love your faith and choose to wear a rosary, cross, saints medal or any other religious item then I don’t see what is the big problem with it.