I'm increasingly shaking my head over stuff like this: "non-functional aspects of the platform (how the platform performs) rather than its functional aspects (i.e. what the platform does)" as those two were separable. Try this as a heuristic: if it doesn't perform, it doesn't do.

A functional/non-functional divide for requirements, or problems, or testing seems very peculiar, affording a kind of dismissal of usability, reliability, accessibility security, performance, compatibility, etc. problems. "Well, those are only *non-functional* requirements."

Or, if you like: how is a performance problem *not* a functional problem? How is a reliability problem not a functional problem? Where do we get the idea that a software product is about functions and only then about all the other stuff?