“Rolling your own” cryptographic system is rarely a good idea. There are countless examples of companies and governments deciding to ignore existing tested and verified standard industry tools on the basis they’re more vulnerable because they’re more well known, but that decision tends to bite them in the end because the solution they come up with has some critical vulnerabilities they didn’t notice in time. These things are easy to miss when there isn’t a whole global community of security professionals looking at the code.

Now I’ll admit that the US government could absolutely create a comparable or even superior solution if they put the right people and enough funding behind the project, no doubt. There is the question of whether or not it’s worth doing, worth the investment. If budgets are tight (because conservatives are so concerned about govt spending 🙄), I’d certainly rather they use signal than they decide to dedicate almost enough funding and develop something that almost works; that could also be disastrous.

Honestly, the best move for the government is probably to make their own app utilizing existing standards. The signal protocol is perfectly open and free, they just need their own clients. Well, that and some identity verification in the account creation process. But yeah, If they had their own app, they could design it to do some useful things, like verify all members in a group have appropriate security clearance. That might have come in handy…

So yeah, I don’t really disagree with you, they should probably be using their own system. But I think it’s easy to think that any bespoke system would inherently be superior, and that very much isn’t the case. And with that in mind I’d say it’s truly not a crazy or negligent choice to use the existing best-of-class systems off the shelf. It’s maybe not the best choice, but it’s not a bad one.