To try and defend him a little, it is hard not to shoot the 3 in an uptempo style offense where your other 4 starting teammates are shooting the trey with success. Not to mention Childress when he comes in. I think Chism is still searching for his game and gets nervous that if he does not take that shot, then he will not get another touch in that posession.
That being said, I think those banked treys are serving more harm than good over the long run for Chism. He definately needs to work the paint more.