I read your comment and understand that you're not saying the two terms are equal, rather, you're trying to demonstrate that it is not unusual for someone outside of the persecuted group to be offended by words intended to offend members of the persecuted group. Yet, were I the type to take offense, I might find it quite offensive that you used what is widely considered the most offensive word in the English language to make a hyperbolic and inapt analogy.
The word 'nigger' is a pejorative racial slur intended to wound when it is used, whereas the word 'bro' is commonly associated with friendship and brotherhood. And douchebag frat guys.
I'm not.