Socially speaking, I find it's easier to see gray. When you run into somebody in a social situation who knows you see him as heinously immoral, or maybe just a little bit of a sleazebag, there's tension. The tension is likely to get to him, causing him to needlessly bring up the issue in some contrived way. At that point, there's a magic phrase to completely banish the tension: "Well, yeah, shit's complicated." Suddenly you can be best friends.
I learned this trick when I was a strict vegetarian. I wasn't eager to confront people about their meat-eating, but when you don't eat meat, people pretty quickly jump to the conclusion that you think they're morally wrong to eat meat. The tension bothers them, so they bring it up in some awkward way. When my girlfriend's father did that (and later at one point her boss, at a company barbecue) I didn't want to get into the details, so I just said, "Well, it's a complicated issue." It was an honest statement, and I really had no idea exactly where I stood on eating meat, but I was so impressed with how completely it put them at ease and averted all conflict that I stored that memory away. Since then, I have used it many times dishonestly to avoid conflict with people who had power over me, my friends, or my family. Seeing gray is a "get out of conflict free" card.
I think the only time it takes bravery to see gray areas is when everybody else sees black and white. Otherwise, the "ability" to see gray helps you paper over disagreements and maintain valuable relationships with people.
Also, it usually isn't correct to think that a person avoids addressing gray areas by being black-and-white on a certain question. I am single, and for me, sex is an endless gray area. I have a conservative Christian friend who doesn't see any gray at all when it comes to premarital sex, but not because he's stupid or unthoughtful. He has to deal with gray areas in other places, such as divorce and state-mandated immunization against HPV. (His daughter will be immunized, and he thinks that's okay. He has friends who think it's not, and who are shocked by the fact that he doesn't resist in some way.) RMS sees gray areas in the use of non-free technology, and he makes concessions to reality. He's proud of his ability to use a completely free computer system, and he understands that it isn't practical for everybody, and he knows that even his success is limited to a very small portion of the technology that contributes to his existence. That's a gray area! I can understand where he's at. When I was a vegetarian, and now as a near-vegetarian, I know some people might think I'm being black and white to subsist on beans and potato salad at a catered barbecue lunch, but I think I'm being plenty "gray" by eating beans from a barbecue joint without asking why they taste so darned good. Everyone's thinking is gray someplace; the perception of "black-and-white thinking" is created by an observer focusing in on a certain place where he expects to find gray and is surprised to find black or white instead.