Except that this perfectly describes the current ultra left. I was a part of it. I've seen it, I've interacted with t, I've been it.
Why is SJW so offensive? Because conservatives use it? So now is snowflakes a pejorative too? This is a classic example of the partisanship happening in America. Why legitimate criticisms are tossed away because "conservatives say that". You can't get around the fact SJW is the perfect descriptor: someone who cares about social justice (a fantastic and legitimate cause) but is a complete and utter warrior about it. It comes to a point where being a warrior makes all other people who disagree with you into an enemy. That's the nature of warriors. Eventually, it's less about social justice and more about fighting people who don't share your ideology.
SJW is the perfect word for this kind of person. The fact that it has been coopted by conservatives is kind of besides the point. What should matter is the content within someone's message. If we mostly agree but I find either a. your message too extreme or b. on the right track but misguided and could be used with that kind of vigor elsewhere, are we really enemies?
But nah, SJWs class you as an enemy just by using SJW truly embodying the "warrior" part of the term. We don't have a word for people who don't put words into action. We could use coward, hypocrite, whatever. But SJW fits just as much and cuts deeply into the issue.