For a program consistently preaching how it doesn't like to slap redshirts on its freshmen, Ohio State has done so more frequently than Urban Meyer would prefer at various points of his tenure.
Excluding extenuating circumstances, the prevailing logic is to keep a player's eligibility clock running. Elite guys are going to leave after three years with the program regardless, and for those that might ultimately become recruiting misses, keeping their scholarships on the roster longer than necessary creates bubbles within classes and decreases the scholarships available that would otherwise be handed out to the next potential blue chip.