A huge part of it is recruiting. As they said in the article...
"Of course, recruiting elite talent certainly aids in sending kids who are basically destined for the league to the league, and as you could expect, it’s another area of college basketball that’s simply being overwhelmed by Calipari and the Wildcats.
5-star recruits between '09-14 UK: 23 Duke/UNC/Arizona: 8 Texas/Kansas: 7 Cuse/Florida/UCLA: 6 Calipari has a clear monopoly in recruiting"
(Although I am not about those numbers...)