they are young enough that their overbearing, borderline personality narcissistic moms still control them. this is ALL on the moms. I have seen these boys competing as girls. it's either, former-college-athlete mom didn't get the daughter she wanted so now Timmy is gonna be Tammy (to allow her to relive her glory days) OR Timmy is a bit light in the loafers which embarrasses her and she'd rather have a "daughter" than a gay son. and then she needs extra juice out of THAT situation so she pushes him into girls' sports. Sports dads are famous but sports MOMS are terrifying, oftentimes. they are INTENSE. this continues because a) no one wants to confront these women and b) people feel sorry for their sons tbh.