The six key principles of MLK’s tactics . Does this look like the playbook of most of the so called justice warriors we see covered in the news?
First, one can resist evil without resorting to violence.
It would depend on what form of "evil" one is dealing with. Evil ideas can be resisted and fought with other ideas. If it's evil accompanied by force and violence, then that may be a different matter. MLK borrowed from Gandhi, and they were both faced with seeking justice for people who were oppressed, unarmed, and mostly powerless against the most powerful military machines ever devised. No chance of winning an armed confrontation against such a powerful force, so other methods had to be tried.
Second, nonviolence seeks to win the ‘‘friendship and understanding’’ of the opponent, not to humiliate him (King, Stride, 84).
I would agree with this, at least in situations where it might be necessary to gain hearts and minds of the masses. It also depends on how one defines one's "opponent." The tactic of non-violence was more designed to appeal to the sympathies of those "on the fence" or who are already predisposed towards sympathizing with the oppressed. In MLK's case, he was trying to politically isolate his opponents and expose them for the hateful racists that they were, while still trying to gain sympathy among the majority of whites and the political establishment which had an enormous stake in trying to prove to the world that it supported freedom, justice, and equality.
Third, evil itself, not the people committing evil acts, should be opposed.
I never could really understand statements like this. If "evil" (however one defines it) doesn't come from the people committing evil acts, then where is it? Where is this thing called "evil" that we must oppose? Is there some evil dark crystal emanating waves of evil energy in some cave somewhere? Then we must find it and destroy it.
Fourth, those committed to nonviolence must be willing to suffer without retaliation as suffering itself can be redemptive.
Suffering can garner sympathy with a lot of people. It can create a certain level of outrage and political energy which can be enough to move politicians to order armies into action - and that's when the violence begins. So, the idea of "nonviolence" is compelling on a surface level. "Turn the other cheek" sounds so righteous and spiritually moral, doesn't it? But if you scratch the surface a bit, it seems that "suffering" is also a political tool, which can indirectly lead to incitements of violence in others.
Fifth, nonviolent resistance avoids ‘‘external physical violence’’ and ‘‘internal violence of spirit’’ as well: ‘‘The nonviolent resister not only refuses to shoot his opponent but he also refuses to hate him’’ (King, Stride, 85). The resister should be motivated by love in the sense of the Greek word agape, which means ‘‘understanding,’’ or ‘‘redeeming good will for all men’’ (King, Stride, 86).
This makes sense to a point. There's also the practical consideration that the typical nonviolent resister would be mostly facing opponents who are/were low-level "pawns." It's unlikely that they'll ever know or be able to meet their true "opponent." Similarly, some might believe that it's wrong to hate the low-level pawns or the misguided masses who may not know any better, but reserving a certain level of hatred for the top leaders might be warranted.
The sixth principle is that the nonviolent resister must have a ‘‘deep faith in the future,’’ stemming from the conviction that ‘‘the universe is on the side of justice’’ (King, Stride, 8
I don't know if I could ever believe that "the universe is on the side of justice."
All in all, to answer your main query, social justice tactics are political tactics, and as such, they manifest themselves in whatever form is politically expedient. It's no different with any other political ideology or faction.
Whatever differences one might perceive between now and then appear to stem from the fact that, back in MLK's time, those fighting for social justice and civil rights were fighting an uphill battle, swimming against the current and dealing with an intractable yet still very powerful opponent. Nevertheless, they eventually won that battle, and society has changed immensely since the days of MLK.
Nowadays, one can say that the "tables have turned," and that what used to be "anti-establishment" has now become the establishment - and vice versa. Those who were deemed "radicals" and "terrorists" in the 1960s eventually became respected professors, authors, politicians, etc., while guys like George Wallace had to "reform" themselves or be left behind in the dust. Whatever changes in "social justice tactics" seem to be linked to their past successes and continued prevalence in the political culture.
The main complaint that I see regarding the whole "SJW" thing is that they don't appear to practice what they preach. It appears to some that they've somehow lost their way and forgot the original cause they were fighting for.
