Well of course, it's not 100% true- who said anything about 100%? There are theoretical branches of computer science; but most of computer science is not purely theoretical. Certainly machine learning (and more broadly speaking, much of AI) is like I say.

I'm not sure who brought up a schematic? The bit I quoted is taken from the paper and it's a clear attempt to motivate the paper's approach as having a practical application. To clarify, do you disagree with that?