I can see how there might be situations where "let me play devil's advocate" is an important tool to ensure that there are no surprises, where scientists pop the fantasy bubbles of other scientists and insist that they speculate about different outcomes

Take perhaps the example of the Challenger exploding:

Roger Boisjoly: Let me play devil's advocate. What if the cold weather causes the seal on the O-rings to fail?

Actually Roger did warn them, but no one listened. Was it a lack of trust or an overwhelming desire to not delay the project any further?

Making decisions about other people's life-or-death situations should require questioning all aspects of a project. I have no objection to that. It just seems that the phrase "let me play ..." makes the process seem less sincere.

Instead of bringing up the an argument that way, I'd begin, "I'm wondering whether you considered this."

I'm being idiosyncratic here. The phrase irritates me and I find it is often used to not really listen to the other person. Instead of arguing the opposite of what someone offers, first make sure you have really listened to them and understand them before challenging it.

Other phrases irritate me. One is this: "With all due respect" - it seems to really mean, "I think you're an idiot."

But that's a topic for another day.

BUT At the end of the day, regardless of what the person values, if they did actually poke holes in your argument, you yourself should be self-reflective enough to be able to examine why that is. Perhaps it's the context, and perhaps it's because you're wrong.

Thanks for your thoughtful reply and explanation.