I was talking to a parent recently and she was telling me about her son wanting to join a baseball team. She said he liked the idea of being on a team but she didn't know if her son knew what it took to be a teammate.
It is a great observation. Kids have to be able to handle structured practices, rules, discipline, and have the ability to be responsible, role-playing and caring. Plus they must be coachable and willing to learn.
Not everyone can do that and that is why it is important to identify whether a youth player is a dreamer or really wants to try hard to be an active and positive participant.