It's probably unwise to think prosecutors and federal agents are stupid. They were in the 1990s crypto wars, but not now. What we tend to perceive as 'stupid' is in reality, 'powerful.' They don't need to explain themselves, because they put the onus of compliance on you. Gaming out the subpoena, Signal does not have this user information because it does not exist, but it does have server locations, 3rd party service…
This is one of those posts that sounds truthy because it makes a bunch of broad assertions. ;) Legal systems are peopled by people. Just like other systems. Unlike many other systems, the American legal system is in fact highly distributed—so it's hard to say things like "The System is out to destroy you"; individual agents of that "system" might have different, misaligned, or antagonistic goals. Much of this is by d…
What if there's a misconfigured logging server that has information that can be used to identify users? Well then that's now going to be given to the government and if Signal tries to turn it off they'll be liable for destruction of evidence.
The actual employees of Signal know internal details of if something is poorly implemented and leaks useful information or not. If the government rattles the cage hard enough, they think they might find someone within it that will give up that information.