Well, back then we couldn't select platforms for accessories, that's a newer feature and I didn't think to go back and update them 
I just submitted updates for the six accessories I added last year but you'll probably find other accessories that simply say "Accessory" as the platform. If you know what they are for you can submit an edit with the correct platform 
I am aware that that listing accessories for specific consoles is indeed a newer feature. I would have just edited it to reflect that, but I didn't want to mess with your collection. If I would have renamed it 'XBAND Genesis' and you had the SNES one I would have made your collection inaccurate, which I really didn't wish to do.
Even before accessories got their own page per system, it was still typically better to not generalize something that had multiple versions for multiple systems (IE something like 'Gameshark - Gameboy' vs. 'Gameshark - Nintendo 64')
