Also though, if you know you're not taking your kid, couldn't the adult just buy a ticket somewhere else in that stand and then sit in the kid's seat so you're together? There have been singles available at every game even though we've been top all season. It's not for the club to subsidise people.
They make a slightly different noise as well.
I'm assuming six is what they think the max number of home night league games are so this is there to stop people buying a child ticket and upgrading it every game (which may be cheaper or just a PITA for the admin team). I upgrade my son's for...