The security vulnerabilities the NSA would use to spy on a system, or even just use as a jumping point to another system, can also be used by bad actors for other purposes, such as screwing with people's water.
Absolutely true. It's just tiresome to hear internet people decide the NSA is $GENERIC_VILLAIN when they're an intelligence agency with a given remit. Of course their job is to hack and penetrate foreign systems to get intelligence information for the Federal government. That's well-documented. But that's not the same as claiming their job is to create chaos for $PARANOID_REASON. That's internet tinfoil-hattery.
I don't think anyone was claiming that or anything remotely close to it. I was explaining why the NSA wouldn't necessarily be in favour of more digitally secure infrastructure, because you seemed to be the only person in the thread who didn't understand.