You need to be able to argue in favor of multiple positions, theories, hypotheses, and points of view, including the ones you believe aren't accurate. Even the ones you happen to think are dangerous—it really behooves us to understand what arguments are in favor of the danger. Someone out there is working from that blueprint, and it's safer if you understand it and can calmly enlighten anyone about the mistakes in it.*

We've got this expression, "playing devil's advocate." It's a really important skill, but sometimes I think the name is unfortunate and misleading. Putting "devil" on there puts the cart before the horse; sometimes the devil's advocate position is absolutely right, and either way, I don't think the devil has much to do with this. "Playing devil's advocate" can be compared to "the devil is in the details," and in both cases it's about the thing you overlooked turning into a problem. If you DON'T play devil's advocate, that's the devil in the details that you missed. By NOT playing devil's advocate, you invite the "devil," or in other words, unexpected dangers and difficulties.

Very often when you play devil's advocate, you'll either annoy people or get them downright suspicious of you. People who don't want to make waves or seem suspicious will avoid this out of decency, and might even end up believing that to think in such a "devilish" (troubleshooting) way is wrong and dangerous. They'll block certain lines of thought from their minds and treat any mention of these lines of thought by others with stigma.

It doesn't take a lot of imagination to see what just happened there. A misguided moral instinct ruined a group's ability to talk issues through thoroughly and accurately.

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*(It's also safer if your copy of the blueprint is completely accurate, rather than biased by upset, your personal moral code, and judgment. Many people, people of all stripes, can spot personal propaganda and straw man arguments and when they do, it undermines you.)