It's been a long time, but I remember us having this discussion in the very beginning. It was decided to list the categories by the name they were marketed under. You never saw anything that said "Nintendo Super Nintendo", just "Super Nintendo". Also, I don't seem to remember anyone saying "NEC Turbografx 16". I think it makes sense for the Sega consoles to have "Sega" in front because that is always how I heard them marketed back in the day. It was always "Sega Master System" or "Sega Genesis" etc.
This could get really tricky though. In actuality we would have things like Super Nintendo Entertainment System, Panasonic R.E.A.L 3DO, Family Computer (since Nintendo didn't advertise with their name in front or label it as Famicom). I guess it comes down to how "marketing" is defined (What was in ads, what was on the system, what was on the box).
I'm an analyst so I get picky over defining things and creating rules that apply to all data. Not trying to start any fights - just giving my opinion.
