The problem is that there doesn't seem to be a strong movement for Maintaining Decent Treatment for All People.
Well, usually that doesn't fall under the rubric of a political movement at all. We just call it civility - a core moral value of any physical community where people seek to be protected from bodily harm and thrive in a nurturing environment.
If there is any political question here, it's who or what should be included under "people". Folks who are similar enough to you in e.g. culture that you can intuitively trust them? Any Homosapien's? Any Hominidae (i.e. including other Great Apes)? Other animal species on a case-by-case basis, such as dolphins and whales? Robots and other man-made intelligences? Corporations?
But it's quite unclear how deferring to the so-called "social justice movement" would be helpful in approaching these hard questions. It seems that their "politics" is much too simplistic, so they just ignore them.
You've underestimated what a Maintaining Decent Treatment for All People Movement would cover.
It might be pacifist. It would certainly be very cautious about war. It would be pro-refugee.
And push for a rational justice system. civil behavior by police, and good prison conditions.
Oppose domestic violence, and be emphatic that this applies to men, women, and children.
Oppose bullying, both in schools and workplaces.
I'm not sure I've included all the major categories.
A lot of this isn't being done reliably, and some of it faces a lot of opposition
I'm not going...
A long blog post explains why the author, a feminist, is not comfortable with the rationalist community despite thinking it is "super cool and interesting". It's directed specifically at Yvain, but it's probably general enough to be of some interest here.
http://apophemi.wordpress.com/2014/01/04/why-im-not-on-the-rationalist-masterlist/
I'm not sure if I can summarize this fairly but the main thrust seems to be that we are overly willing to entertain offensive/taboo/hurtful ideas and this drives off many types of people. Here's a quote:
The author perceives a link between LW type open discourse and danger to minority groups. I'm not sure whether that's true or not. Take race. Many LWers are willing to entertain ideas about the existence and possible importance of average group differences in psychological traits. So, maybe LWers are racists. But they're racists who continually obsess over optimizing their philanthropic contributions to African charities. So, maybe not racists in a dangerous way?
An overly rosy view, perhaps, and I don't want to deny the reality of the blogger's experience. Clearly, the person is intelligent and attracted to some aspects of LW discourse while turned off by other aspects.