I've theorised this myself but remain quite sceptical.
When I was kid it seemed lots of kids had either nes or a gameboy. Yes, sega did well, and sold many more megadrives and seemed to have an ok masersystem presence in kids homes. But don't think kids weren't playing lots of Nintendo.
Segas popularity meant I (as a Snes owner) was always on the smallest team in a silly fanboy argument. But kids were always talking about SNES games with other kids at school. Everyone knew plenty of kids with nintendos even if they only had a sega and kids would go around to each others homes and get to play both brands.
And then there was the crowd at school that I retrospective label the Amiga master race.
Nintendos big fail was in the playstation generation. Many people who began gaming then went on to never even touch a nintendo game.







