There is a difference between a 'fan' and a 'supporter'.
I've got 7 cousins on my mum's side, and they would all say they support Liverpool if asked. I'm the only Everton supporter and I've been going the match my whole life. Collectively, they must've been to about three games, and I'm not exaggerating.
Probably the same in school, we were outnumbered, but the four Everton fans in the class would actually go to the game.
They're just the easy option to be a 'fan' of.
I don't class them as real football supporters, and never will.