As I see it, Robotics.SE is very much aimed at the Application, whereas many of the other SE sites are aiming at the underlying theory. And as I commented on Where does Robotics end and Electrical Engineering begin?Where does Robotics end and Electrical Engineering begin? there cannot be a clear demarcation between the application and the principal.
On the other hand, as I've commented elsewhere, we have to be careful about too-basic questionscareful about too-basic questions.
Some questions will be obviously off-topic for R.SE, some will be on-topic but more on-topic elsewhere (and hence probably should be migrated) and others will be more on-topic here, so should stay.
But fundamentally, as long as it is on-topic here, no matter how on-topic it would be elsewhere, then here is fair enough.