Another way to look at it: avoid the open/academic community stop doing xrypto research because NSA mathematicians are (secretly) way ahead of them?

"Open" is a different league from proprietary. It doesn't matter that they are behind proprietary. but it matters when they are working on the wrong problems.

It's unfortunate that, in science, if it isn't written down, it doesn't exist.

Having been bitten by the 'but we already know how to do that' comments, I find this particular aspect of industry to be very irritating. There are 3 possibilities:

The unpublished solution is brilliant.

The solution fits for very limited constraints applicable only to that situation.

The solution is a half-assed hack that only looks like it works.

In only one of those situations is the 'naive' comment valid.

Fair. This happens less in my field, but a lot of that could be because, for medical applications, people are far less willing to certify without published validation.