I just got done with a 4 year college last year. My overall expereince is that those of social justice are some the most intolerant people I have ever met.
Yes. Among social conservatives in this country (and other countries as well), there is this mistaken impression that in the name of "social justice", modern secular liberals are excessively tolerant of all sorts of nonsense and immoral things, like civil rights for gays, or supporting the religious sensibilities of other religious groups like, heaven forbid, Muslims (if you are living in a Christian country), or Christians (if you are living in a Muslim country), and inferior people (other racial groups, poor people, looked-down-upon ethnicities, etc...). But, they complain, we seem so critical and intolerant of the "rights" of the "good people", those with "morality, those adhering to the religion of the majority (for example we have the audacity to oppress and keep good Christians from being able to force school prayer in public schools, or keep topics like evolutionary biology from being taught, or claiming that women who are raped and gotten pregnant must have liked being raped otherwise they shouldn't be pregnant, or, in other societies, forcing them to cover their face with a veil and be kept from voting or even driving to be considered modest and "moral", etc...
But what drives this is a sense of justice. That includes, yes, social justice. Justice means fairness. Part of what it means is watching out for the weakest and most vulnerable groups and demographics in society, for making sure everyone has a fighting chance, not just those in positions of power and privilege (whether it's groups of people due to the wealth of the family they were born into, or the religious groups with which they identify, or the color of their skin, etc...). We need to be tolerant of people and groups and demographics not like us. We need to learn more about them and understand them, and be less eager to judge them and make them more like us. The pluralistic modern world demands it.
But we will not be tolerant of intolerance. We will not be tolerant of injustice. A society which has no sense of justice is not a civil society. It is the jungle, where only the strong survive and the weak get killed and eaten for lunch. No matter how privileged and part of the "in-crowd" these opponents of social justice may feel, they are very myopic if they don't realize that it's just a matter of time before they too will not be in that privileged crowd. Then maybe perhaps the concept of social justice will have more meaning for them.