The misunderstanding people have is that social justice does not inherently have to express itself in socialism despite both concepts having the word "social" in them. Pre-school logic might say that since they both use the word "social" they are immanently linked, but that just is not the case. The Salvation Army grew out of social justice thinking. As far as I can tell, no government intervention there. Just a group of Christians trying to more fully reflect the kingdom of God and transform the society around them by providing the poor with inexpensive clothes and other items. YMCA and Habitat for Humanity are a few more examples of originally-Christian organizations that grew out of that same desire.
People who take seriously Jesus' teaching to love the hungry, give water to the thirsty, help the sick, visit prisoners, and welcome strangers will look radically different in a society that is a collection of individuals focused on accumulating personal wealth and ignoring those less skilled, educated, connected, or fortunate than them. You can be a good libertarian, communist, or anywhere in between and desire for society to reflect the kingdom of God; our political differences will not cause us to change our goal for society but will alter our approach in reaching that goal.
The issue with Beck deals with one's approach to politics, not the validity or purpose of the social gospel. When it comes to politics, you can either take a hands-off approach, a transformational approach, or a mixed schizophrenic combination of the two. I still struggle with what stance I should have as a Christian in a representative democracy. Beck is obviously in the hands-off realm, and he is battling against those like Jim Wallis who take a transformational approach. Unfortunately, Beck confused the battle as one against social justice, which he then proceeded to link to communism and nazism, two political systems that were natural enemies when they were geographic neighbors who share nothing in common except oppression in their mid-19th century manifestations, when his real argument is that Christians should have a hands-off, libertarian approach to government. Social justice proponents can have that approach, and you will see it expressed in the development of charitable organizations like hospitals, clinics, counseling centers, homeless shelters, thrift stores, etc.
Or maybe there is a bigger difference among us who claim to follow Jesus. Maybe some of us are happy living selfishly and do not desire to see the kingdom more clearly reflected here on earth. Maybe that is the real difference. If so, I am scared and saddened. But I would like to think that the difference is just our approach to politics.