I have no inside knowledge of the situation but the way people interpret his body language may not be correct. Most of us have played sports with people that were not cheerleaders when playing. Those people simply put their head down and play the game. I do not fault anyone for having that personality. I love Naz and his personality, however, a person cannot fault BDJ a bit because he does not outwardly show that same emotion. Not everyone is designed to have that personality, it doesn't mean they don't feel the same way on the inside.
I agree with you totally here. Body language of a kid that is truly trying hard, having a bad game and just being frustrated with themselves, not teammates can look awfully selfish. Maybe he is frustrated because he is failing his teammates. Nobody thinks of this typically. Maybe he thinks he isn't helping as well as he should. I never see him barking at his teammates at all. You know who I did see barking at their teammates a lot, and it could have been interpreted much different than it was, especially given his history, Deandre Kane.
BDJ would be much more effective in my opinion offensively if he drove it to the hoop strong and got the and ones, and resists taking all the fadeaways. Kane did that ALOT, the things that typically happen--> 2 shots, and 1s, layups/dunks, no-calls (leads to make-up calls) or rejections. Most of those are positive things. I hope he gets it right, I really do. Its on him now.