Er ... you might as well say "why would a white person be offended by abuse of black people". Just because a particular form of hatred doesn't apply to YOU, doesn't mean you can't be offended by it. I have problems with racism, misogeny and cruel remarks to midgets. I'm a 6ft 4in white man.
Not sure why the OP needs so much grief for asking a fairly innocent question, but that's NSC I guess.
As a straight father-of-three I was subjected to some pretty unpleasant anti-gay stuff on Facebook yesterday from a Palace fan I've never met or heard of before. (It was on a thread started by...