Because, unless you start a Colts side, you'll never be allowed into the higher divisions.
I'm not against U21 players going up against older men - we've fielded a few 17yo guys in first grade.
But at the same time, not everyone is necessarily mature enough for that, particularly if they're coming back from a schools comp that is only 8 games a year and a variety of match ups
Agreed. It's mainly about confidence for these young guys. For the majority of them they've only ever played against other school boys. To suddenly be playing against older, bigger guys is a big step up for them. Once they get their confidence up they're good to go.
Selection would be based upon skill level but I think that the U21's would be more suited to a spot in 2nd grade.