Earlier quoted context omitted.
What kinds of experiences have shown this heuristic to be not so useful to you?
People often can't see past their own hostility when figuring out what a system 'does'. And now they have have a clever sounding way to pretend that they're describing a system with detached reason, not just describing their attitude towards the system. It's like a art review where a writer - completely unaware of what they're doing - talks only about the work, but says nothing about the work and opens a window into…
"If we know what a system does, we know that it is its purpose": is that ok?