The so called 'Green Teamers' (that term cracks me up) will say 'oh it doesn't matter...he'll still be great!'. Those of us who have seen more than their share of Celtics head cases over the years see warning signs already. The kid obviously have some issues...but thinking 'Horford will show him' or 'we need Perk to keep him in line' that stuff is so irrelevant.
If this kid has off the court issues it may well be that no amount of coddling, scolding, tough love etc will suddenly turn him around. And Brad may not be able to do it. He can have the greatest coaching/advice in the world and if he's just clueless then it's not going to matter.
The gamble is that he'll figure it all out eventually and develop as a player. What this does though is catch the attention of the Shaughnessy's of the world so there will be some long time media members who will be looking for him to fail. He's got no concept of that - and it may not be as important as it was say 10 or 15 years ago - but he's definitely not helping himself career-wise pulling this stuff.
But given that this is the information age I'm sure that Ainge & co knew exactly what they were getting involved with when they picked this guy.