Its not as simple as in hindsight declaring that this guy or that guy should have redshirted.
The developmental redshirt is not employed nearly as frequently in basketball as it is in football. The kid has to be on board with a five year college experience. How many kids have we used it on who have actually completed five years here? I can only think of Gorman. With the exception of Cooney I can't think of anyone that we've give a developmental redshirt who has actually become a significant contributor...(must be missing someone?).
The focus for kids today seems to be how quickly can I get out of school and move on to the professional ranks, not how many years can I extend my eligibility...especially coming in. Sure guys who have reached their junior or senior year may gain the perspective that they aren't leaving early, but most kids come in with a lot of confidence and may not be easily convinced that they won't be in the rotation.
Ultimately, JB can't make anyone redshirt. It is an election that must be made prior to the season, otherwise there has to be an injury involved. Remember we are recruiting these kids to come here and play. They all have other options. If JB starts telling kids in the top 35-100 range that we are going to give them a developmental redshirt year, I bet a lot of those kids stop coming and go somewhere else.
