The thing with all the Social Justice X ideas is that it's basically the same problem as "SJW", i.e. they are easily interpreted as criticising someone just for caring about social justice. Which is why I like radflake; it sounds distinct enough to suggest something different.
Right.
The whole point of it is that if you include "social justice" in the insult, then there are people that will apply it to ALL social justice advocates, and eventually, people will be unable to tell if you're insulting the extremists or the entire movement.
And don't give me that bullshit about how they should "know from context". That's bordering on "I expect everyone to be psychic and know precisely what I'm talking about even though I use terminology that can only be understood in context that is not always provided up front."
On the other hand, if you take away "social justice" from it, it becomes useful on multiple levels.
First of all, you're not insulting someone just for arguing for social justice, whether you mean to or not.
Second of all, you're removing the social justice connotation from people you ARE insulting. Considering they may take pride on being for social justice, this not only prevents them from building up their ego for being "accused of being for social justice", but it also implies that they're in it purely for themselves, not for other people. Which they generally are.