Hiring college coaches into the NBA has always been a disaster if they were the coaches who had been in college for years. Billy Donovan is the only recent exception I can think of. Countless other failed examples, Pitino, that one guy the Bobcats had...etc. Stevens is the only one that worked out and he was so young he had an easy time adapting to the NBA world where you don't get to cherry pick your roster, play 2x+as many games, can't freely discipline young kids, and have to learn to adapt your offense/defense and not just "run a system." Stevens couldn't really get away from that last one as we saw him get picked apart by Ty Lue multiple times. Beeline was actually one of the worst possible candidates for an NBA coach. You could only really do worse by hiring that guy on your college IM team who was too hungover to step on the court.
I would love it if that guy on the IM team got to be an NBA coach. Perfect coach for a players league, just let them play man!