He typically gets something out of everyone who stays in program, they either develop and have a good monster back half of their career, or they don't develop and a lot of those guys move on.
Fran only needs to point at his 2 starting guards now, Tony Perkins and Ahron Ulis, both who barely played their freshman seasons and both had smaller roles their Sophomore seasons, but have seen their roles, minutes and contributions to the program skyrocket their Jr. years.
I think most level headed players understand that there is an adjustment period and it takes time to ramp up to the speed of the college level.
Those that stick with it and put in the time are going to be a big part of Iowa's program, the ones who don't, again, find their way out usually.