... they are. Except, the question in question is neither a technical one, nor about the system. It is about a message a game ROM displays when detecting (or more exact not detecting) some kind of controller. So it's strictly about that games content, not the console or it's component.
One problem with this is that this meta question, its premade answer and comments make it sound as if the close votes where about consoles per se. They where not.
I believe it's pretty clear that any computing device is by default on topic for RC.SE - despite the purpose it's made for. Just, while the device it self will construct a basic on-topic-ness, it's the questions topic (and details), that must be used for a final classification. A test the mentioned question about the NES message fails in my opinion, as it is not about the computing device itself, or any detail thereof, but the game plugged in and what is coded.
I truly believe that we need to be quite vigilante in defending this fine line to avoid slowly moving the borderline by more and more such questions to be finally drowned in a sea of undesirable content.
LangLangC made a nice comment here about "in 15 years this SE will have to include toasters & fridges". Which I very much agree. Then again, exactly such a questions, regarding an embedded system, has been already closed as being off topic, despite being about a quite classic 16 bit computer system. So, is it only on topic if it has been seen in millions of living rooms and a part of pop culture or should this apply to all computing devices?
P.S.: I did wait on purpose to avoide a heated discussion - and see what additional answers/comments will show up.