Because every season or two Painter and Purdue send an unheralded player to the league whether they stick or not, most get a ton of money and a chance they wouldn't have had almost anywhere else. Going backwards over the past decade you have:
Edey - HS rank 416, Drafted - 9, 2024
Ivey - HS rank 89 Drafted - 5, 2022
C. Edwards - HS rank 302, Drafted - 33, 2019
V. Edwards - HS rank 157, Drafted - 52, 2018
Swanigan - HS rank 33, Drafted - 26, 2017
Hammons - HS rank 74, Drafted - 46, 2016
You go back to his early years he had 4 more over 8 years, so again about every year to two years he gets someone in the league that absolutely shouldn't be outside of Swanigan. If you look at the above a trend that is pretty easy to see is that the draft position has gotten steadily better (as has our team). The pitch is Mr. Talented kid who isn't quite destined for the lottery yet, come to Purdue and we can get you there. There are better NBA feeder schools, but for that second tier of talent Purdue is a pretty great place to get the nod.