When AI.SE was about to be created, there was a divide. A few wanted ML and implementation details to be part of the site; most wanted to exclude them. The final agreement was to exclude---so the current topic list excluding explicitly implementation details and so on.
The reasoning back then was that popular frameworks like Tensorflow, etc. were explicitly asking to question on SO. Questions about Data Science were perceived as much better fits for Cross Validated, etc. So no need to duplicate them here, and take the risk of killing AI.SE before it gets momentum. That was an interesting thinking, and I think the result is okay.
Now it seems that many AI.SE questions are about ANN, including popular subcategories like CNN, DNN, RNN, etc. The community here seems to expect xNN Q&A, so the description and topic list do seem like a mismatch---I concur (and that is how I found your question, searching for such a discussion). Another way to put it: How can we "make a mind™" without talking about techniques and tools we have at present?
IMHO it may be time to update description and topic list, to define a posteriori the scope of AI.SE.
Note:
- The current description does include AGI, though. Terminology is quite vague, but an AGI could be a "set" of "cognitive functions [...] mimicked in purely digital environment." As for theory, models, notions, concepts, the current scope has been carefuly thought through, IMO.
- Let's keep in mind that AI.SE is the 3rd attempt to create an AI-related SE site, and the most successfull so far (the previous attempts topped at 6 months before closing). This AI.SE is on something (and the current "market" makes it easier with the DL wave).
Disclaimer: I was part of the first group, so I am biased in my agreement. However the sheer volume of xNN questions might be a data-backed confirmation the site needs an update (I did not go beyond lazily listing and eye-balling unanswered questions).