Scenario 1: Bully calls Meekins a loser.
Scenario 2: Meekins calls Bully a loser.
I think most people would readily agree that, in scenario 1, Bully is verbally bullying Meekins, which is deplorable, while scenario 2 Meekins is performing an act of defiance and should be cheered.
This a clear case where morality is NOT symmetric: When an oppressed person mocks, belittles, or insults the oppressor, it's awesome. When the oppressor mocks, belittles, or insults the oppressed, it's wrong. Substituting one person for another changes the morality of the action.
Got that? Morality is not always symmetric. It matters who you are and what your position is; right and wrong are different for different people in different scenarios.
On to another question: WHY is it wrong for Bully to insult Meekins? It can't be a deontological principle; "don't insult people" would make it wrong for both of them, and a declaration that insulting someone while they're down is a priori wrong is just dodging the question. It can't be utilitarian, either; there is a high likelihood that Meekins comment will result in a beating, more than negating the pleasure of making it.
No, this is a clear case where virtue ethics takes hold. We despise Bully's insult because insulting someone while they're down is the action of a bully and a coward, and we cheer Meekins because insulting the powerful takes courage.
Ah, and there's the rub: the morality of the insult has nothing to do with the prior actions of our two characters. Meekins does not "get insult privileges" as a reward for being oppressed, nor does Bully "lose" them as a punishment. Rather, it is purely a matter of relative power; Bully's power means that insulting Meekins risks nothing, and is therefore cowardly; Meekins, on the other hand, is taking a great risk, which is courageous.
We live in a kyriarchy, which is to say a system of intertwined hierarchies. All else being equal, the rich have more power than the poor, men have more power than women, whites have more power than people of color,* cis heterosexual people have more power than LGBT people, and so on.
Now, this does not mean that members of underprivileged groups get to say whatever they want to members of privileged groups. Morality is complex, and multiple factors interact--generally speaking, an unprovoked verbal assault on an individual is almost always wrong. But it does mean that the bar is lower when it comes to members of underprivileged groups talking about privileged groups in the abstract, because the courage it takes to do so helps counteract the general idea that generalizing about people isn't good.
So, next time you feel the urge to say "people would react differently if you said that about [other group]," pause a moment, and consider this question first:
Yeah, they would. So what?
*You. Yes, you. White person about to comment about how downtrodden you are in an attempt to refute this. Consider two things first: One, are you really suffering because people of color have more power than you, or are you butthurt because privileges you take for granted are being shared with people who aren't you? Two, are you really suffering because people of color have more power than you, or because of some other group unrelated to race (most likely, the rich) have power over you? Any comments of this type which do not answer both those questions will be deleted.