I have tried to figure this out over the years, it seems it is mostly
In the UK and certain out countries in Europe (pointedly not the others in the "multi5" category).
"They were great, we always used to play [list of games]"
Outside the UK
"I think I once saw one when I went round my cousin's house, his parents got the wrong console"
That sounds more like SMS than Genesis. Genesis was incredibly popular in the US. SNES only managed to surpass it overall by staying on the market for an extra couple years after Sega had moved on to the Saturn.