In a video on the bodhi Facebook page, Kimberly Poppe asks an important question here: can we suspend our judgment for a moment? What does this feel like? There has been a lot of controversy on mindfulness promoting non-judgmentalness and thereby condoning injustice, bigotry and violence in the world. I think what is shown here is that it is not about getting rid of judgments altogether, but rather taking a moment to first perceive what is, in a way that is as unbiased as possible, and then engaging in a way that is usually a lot more sane because you had a chance to think it over.
In this way, mindfulness can allow you to not become a zombie, but in fact allow you to see injustice more clearly and act in a more skilful way. By reducing the reliance on forming an opinion before you have had a chance to actually see, you can potentially go beyond your habits of thinking, especially those habits that are quite "sticky", i.e., those that involve your hopes and fears. Instead of running through patterns such as "I am a worthless..." or "s/he probably thinks I am a loser" or "these people are really stupid" again, and thereby making them stronger, we can also have a fresh look at what presents itself. Then we may be able to see different sides of a situation, and choose to do something different than the thing we usually do. So we can still have a strong opinion, and a strong commitment to act on an unjust situation, but now it is founded in a bit more of a grounded response.
Georges Dreyfus has a much more scholarly discussion of this topic: http://www.ahandfulofleaves.org/documents/Articles/Is%20mindfulness%20present-centred%20and%20non-judgmental%20A%20discussion%20of%20the%20cognitive%20dimensions%20of%20mindfulness_CB_Dreyfus_2011.pdf