I guess it's asking a bit much of u12s to think like adults, but if I see a kid taking a dumb shot (even if it goes in) when there was a clearly better option, then I’d call a Strike on that kid deserving to make any high-level team I coach.
Other negatives I’d call strikes for include
- blatant self-obsession such that they only care about themselves, and get hostile or negative when they’re taken off or told off
- dissing teammates when the teammates make mistakes, or being Teflon by trying to find someone else to blame for their own mistakes
- unwilling to follow coaching directions, particularly if it’s because they’re following parents’ directions instead
- one-way runners or 'passengers’ - they only work when there’s something in it for them
- excessive emotion getting in the way of commonsense and judgement, including arrogance
- missing training or tryouts without good reason, or showing general disinterest during them
Any of those issues are going to make life tough for a coach. Coaching and integrating a bunch of kids is hard enough without having to also tread carefully to manage players with emotional issues, unrealistic expectations, selfishness, controlling parents, lack of dedication to the team and the coach, ...