I agree that you should encourage him to move up and try it. If it's not an enriching experience, he can choose to leave at any time. Perhaps he'll feel better in the long run if he gives himself the chance to expand his horizons by doing things that don't come so naturally.

My oldest son put in one year with the BSA, then decided that it was too hard and there wasn't enough fun for him. My second son is enjoying BSA, and it has stretched him in many ways. He is more responsible and resourceful than he was a year ago. He has learned some hard lessons (like get your book signed immediately, or the leader may not remember that you did such and such at camp, and you'll have to do it all over again!) but overall, it has brought him a sense of empowerment and some new buddies. He has his eye on eagle.