Anecdotally I believe it occurs in a much lower amount, I haven't seen it at all as an Indian Muslim. Still I don't deny that it happens, especially in areas with less education. By creed it doesn't make sense-- as a popular hadith says "no Arab is better than a non Arab and no white is better than a black, except by piety and good deeds". Of course this hasn't stopped the ignorant in the past(unfortunately)