It may be the case that the failures of the ability of the machine (2) are best expressed by reference to the shortcomings of its internal workings (1), and not by contrived tests.
It might be the case, but if those shortcomings are not visible in the results of the machine (and therefore not interpretable by a test), why do its internal workings even matter?
I'm saying best expressed. Like, you see the failures in the results, but trying to pin down exactly what's the matter with the results means you resort to a lot of handwaving and abstract complaints about generalities. So if you knew how the internals had to be that would make the difference, you could lean on that.
