That there is also something somewhat problematic with the "social justice" solely based brand of Judaism (I most definitely am NOT calling out Mobius on this one, at all. There are many people though who oversimplify there Judaism in any number of ways, social justice just being one).  Here's my objection...

1) Those who say things such as, "Well, I'm not really religious, but I do believe in tikkun olam." entirely ignore that Judaism is (amongst other things--peoplehood, of course) a religion. One that we all choose to belong to or not, in any number of ways. I don't want to state the obvious here, but religion is pre-disposed by ethereal ideas of G-dliness, the order of the universe, etc...This isn't to say that the "tikkun olam-only" folks don't consider these issues.  What I am saying is that good deeds does not a religion make alone.

2) If one were to accept the solely social justice model as a mode of religion, it seems to be somewhat chauvenistic towards other religions, agnosticism, atheism, etc...Who is to say that one cannot believe in reparing the world and not be a Sufist, Hindu, etc..It just seems like a convenient way to pick-and-choose.  No less than if I only were to give zakat would I be considered a Muslim.

Certainly I am not claiming to ever chime in on the "who is" and "who isn't" debate. I suppose that really all that I am trying to say is that the social justice ideal has been somewhat run with by many people.  And just in the same way that our religion can't be defined by tefilah alone, it is impossible to ever define something so complex (philosophically, religiously and historically) by one concept.