You don't give out 13 scholarships all at the same time, every year. So, a player is not 1 out of 13, they're more like 1 out of 3 or 4 (depending on the size of your recruiting class). Therefore, you have to be much more judicious in who you offer scholies to .
I realize that not every player is a 5 star, but, with attrition, injuries, etc, you have to have a bench without much drop off in talent.
Again, just not sure where a player like Kramer (a defensive specialist with limited offensive skills and lacking a reliable jump shot or outside threat) fits into today's Purdue teams.