"Actually, irrationality is at the heart of it. As with global warming denial, the argument for back doors is a denialist argument against all evidence and against all expert advice."

It would be a lot easier if that were true, but it's not.

Examine all the reasons why backdoors in encryption are bad. Then ask yourself, which of those bother the government that wants to do survelliance?

None of them.

When the adversary pretty much wants everybody to conduct all their business in plain text, and if that's bad for them, too bad so sad, pointing out that we can't very well partially weaken encryption is a non-argument to them.

The only thing that slightly bothers them is that ultimately, government power is significantly based upon American businesses being successful (they provide the tax base, directly and indirectly), and if the encryption weakens American businesses it therefore weakens their own power. That's why they're even slightly listening, and why their line to date has been variants of "Can't you just try harder?" From their point of view, the only thing that has to happen is that customers of American businesses need to be convinced that they are secure; real security is to them a fully separable concern only loosely related to perceptions.

I personally would observe that over time, perception of security and reality of security would tend to synchronize, but one thing you must understand about government or it will forever be mysterious to you is that it is full of people who are used to creating perceptions, wholesale, with varying and often small relationships to the truth. Watch the next high-level policy debate that happens on CNN and Fox, and yes, I'm deliberately picking mass media because it's actually where it is clearest to see. Note how the debate is almost never about facts, real facts, provable and disprovable facts. It is about manufacturing perceptions, and the other side trying to manufacture a perception that fits into people's heads more easily and therefore wins out. If you try to argue that actually weakening security will directly, via facts, create a perception of weak security, you are almost literally saying words that they can not even represent in their brains.

Perceptions don't come from reality for them... perceptions are created, by acts of will and clever spin. When we technologists say that people will perceive our stuff as insecure and not buy it, the solution that leaps to their mind is to use their usual tools to create the necessary perception, then weaken the security under that cover, and to them, we sound like children who believe that reality somehow creates perceptions independently and reliably in people, which to them is snicker-worthy childish naivity.

And worst of all, they're being rational. It works. All the time. Even here on HN in a lot of other of the perennial debates. It's very difficult to rationally argue them out of this position because rather a lot of the facts support their view.

A disturbing number of them accept the perceptions created as a whole as reality even though they are witnesses to or authors of the creation of perceptions themselves, so a disturbing number of these people on one level or another essentially believe they are creating reality. (I find this observation an incredibly important aspect of understanding how the very highest level of politicians operate, as after decades in this world, most of them fit this.) It's basically that observation about how when you read your own field of expertise in the paper you see how crap the reporting is but still believe the other bits of the paper, writ large. Others realize the process consciously to one extent or another and are simply cynically exploiting it.

Now, I believe the technologists are still correct, because for the most part, security purchasers at the high end are fairly rationally evaluating products, and real weaknesses will create perceptions of weakness, and probably little to nothing the government perception-writers can do will change that. But it's hard to explain the government how this is one of those rare places where the engineering and the math are just too hard and too rigorous, the connection to reality too direct and too strong, for their toolset to be of much use. They encounter that situation so rarely they don't really believe it exists.