Who was the last JUCO guy out there that was really a 'game changer' for a team.
Dwight Hardy has absolutely been tearing it up at St John's this year(Indian Hills JC, IA), but he didn't really reach the "game changer" status until this year.
Gary Flowers(Chipola JC) has been a CUSA POY type at So Miss.
There's probably a few more examples out there of recent "game changing" JC transfers, but I believe your premise is correct, tough to find a real difference maker from those ranks these days.