That's the problem. Elliot does recruit liberos...McCoy, Brooks, Yogi, Palmer, Olschwanger, Rounsaville, Hahn, etc. were all recruited specifically for the libero position competition. While a lot were walk ons, they were all highly touted. Go to the archives of volleytalk and every year it's the same- posters getting all excited and singing the praises of the next defensive recruit (before coming onto campus and not panning out). Even Olschwanger was honored as a 'Defensive Dandy' by PrepVolleyball magazine. McCoy was one of the top 2 liberos of her class. Petersen has been recruited since 2015, back when she was just a sophomore in high school. I know the current Stanford libero Hentz was also recruited by Texas.
Thus the problem is development, which brings the spotlight on Sullivan- the defensive coach.
Actually, the libero position is pretty unstable on the national team. I think the US is going to go with a converted OH into L at this World Championships in Japan this year.