And some of them make premature decisions to go early. Cal has said this in so many words regarding Teague, Goodwin, and a few others.
I get the whole "they lose a year of earnings" and "strike while the iron is hot" rebuttal, but some of these guys cost themselves even more money by going early to teams that had no real investment in them.
Additionally, UK features a disproportionate amount of recruits who treat additional years at UK like the plague.
I also get the curse/blessing of how the system works; I'm only saying there's no monolith of logic in their decision making, and as fans we're not obliged to pretend that these early entry decisions represent the same output of wisdom.