...I think Chatman was a casualty of the culture that was present on the team during the end of Rose' era. I think Toolson left for the same reasons (mho). With Nick Emery returning as a floor leader and Haws returning from his mission I think neither Chatman nor Toolson felt they had a place in the offense or fit on the team. I think if the current culture and lockerroom were part of the team then, both guys would've stuck around.
Obviously Chatman turned out to be a very productive player once he left BYU, same with Toolson. Leaving BYU worked out for the best for them. For every freshman wonder-kid there are more kids who need time to develop and don't shine until their 3rd or 4th year for a myriad of reasons (Toolson, Chatman, Anson Winder, Elijah Bryant, Noah Hartsock, Cummard, etc). Even Jimmer didn't really explode until his junior year.
CB needs to stop expecting all of these guys to come in off of their missions or out of high school and be instant superstars year 1.