A lot of posters said that the Celtics have no star so should be taking the player who has the best chance of becoming a star or the player with the highest ceiling (which isn't the same thing as taking the best player available). I've been pointing out that if this is true, the Celtics shouldn't be afraid to take a guard.
A couple of issues with this
(a) It's hard to become a star at the guard position in today's league unless you have outstanding size and athleticism or a fantastic outside shot. Rozier has the athleticism and good speed, but he's small and his outside shot is poor.
(b) It's difficult to develop into a star if you're the third string point guard. The Celts have invested significant resources into Thomas and Smart, so a path to playing time is unclear at this point. Perhaps they'll trade Bradley and Turner and go with a super small backcourt full-time.
Ainge is pretty good at spotting quality players with the basic profile that Rozier presents. I expect he'll be a decent rotation player in the NBA. Unclear how he'll contribute much to this Celtics rotation, though, and it's not like the team was lacking in solid rotation caliber assets.
Of the players the Celts drafted, Hunter probably has the highest upside. He looks a bit like Kevin Martin or Korver in the clips I've seen of him. But he also shot a very poor percentage from three in college.