I didn't read the article, but I would point out that it's next to impossible to accurately assess "development" across teams. These players don't play in a vacuum, and progress is heavily reliant upon the talent and/or ability around you.
For instance, a 3-star receiver at Ohio State immediately has a much higher ceiling than, say, an identical player at Iowa. One will be surrounded by talent that not only elevates his stats through better offensive play, but said talent also draws attention from defenses giving him more opportunities to succeed.
Iowa does a respectable job with development. At one point a few years ago, it was second only to Ohio State in the B1G in terms of number of players in the NFL. Not too shabby. I guess that's one of the reasons the inconsistencies and weak links (... see OL and QB recently) year after year is so maddening.