I'm not sure why the Pistons haven't had him there for an extended period. In hockey, teams are much more willing to use the minors as a developmental tool. The Wings have Simon Edvinsson, a very promising defenseman who's good enough to play in the NHL right now, but he wouldn't get the minutes that he will in the AHL...and in the AHL he'll be on the PP and PK and on a top pair defensively.
Why not send Hayes to the G league to work on his overall game for 30-35 minutes a night?