There are currently 62 former Ohio State football players in the NFL according to ESPN. Nearly all played under Urban Meyer or Ryan Day. Meyer reestablished the football program as an elite one and Day is building on that pedigree.
College success does not directly correlate to professional success. There are a lot of factors that play into a successful professional career. Plenty of college stars enter the league and never live up to their potential, but why is that?
Success has a lot to do with culture. If an elite prospect is inserted into a below average culture, a losing team and a cancerous locker room, it becomes magnanimously more difficult for that player to succeed.