I think it has a lot to do with what you grew up playing. I still play 8bit to this day but I grew up playing them.
Part of it I think is nostalgic and such games being seen as classics. I would offer as well in same case, that there are those gamers who look to 8-bit and 16-bit games because of how often they tended to be more difficult, wanting that challenge. Plus, simplicity in design can often be appreciated. Where because graphics isn't the selling point for these games are they are so often today. So retro games are seen a callback to when developers focused on other things.