He notes it in the video but the Chicago metropolitan area has pretty strict electrical codes. Everything must run through EMT conduit with fully enclosed electrical boxes. Chicago has some weird thing about preventing fires...hmm can't think of where that came from...

For commercial, this extends to low voltage as well. Freerunning cat6 or speaker wire down walls and through ceilings is often completely forbidden. Personally I think that's a bit much...but with the prevalence of PoE and new standards that increase power throughout, maybe it's not such a bad idea.