Being more athletic isn't the point. You need to have some sort of basketball skill to make it in the NBA. Right now he doesn't have one. He had difficulty getting his shot off against 6'7" players. He won't last a practice in the NBA. Part of Dakari's problem is that right now he wouldn't play over Poythress or Skal either. Even though you can argue that his draft stock would fall some more if he didn't get play time next year as well I still don't think that not being about to get playing time in college is a good argument for going pro.
As for losing money, that would be a compelling case if he were projected as a top 10 pick. Dakari isn't. He may not get in the 1st round even. You only lose money if you are in the range where you are guaranteed to get paid in the first place. I don't see Dakari making an NBA roster next year. He might be able to make money playing in Europe or somewhere but now you are talking money that he can make up for by coming back. Getting drafted on potential is one thing if you are a top 15 pick. Being borderline to make the 1st round is another matter.
His difficulty was being blocked by a secondary defender, because for whatever reason he had a hard time feeling the doubleteam. In one on one coverage situations, he was very hard to stop on the college level. Has very good footwork. Can finish with either hand. Does a good job of being big, which means he understands his role as a big man and doesn't try to do things beyond his ability. He even has decent footspeed for a man his size.
He just has no lift, AT ALL. That wont improve in college, or elsewhere. So theres 2 choices:
1) Stay in college, earn nothing, risk injury, improve slightly on things you already do reasonably well, and hope you move up a spot or two; or 2) Leave, get drafted towards the end of the first round, earn around a million dollars, work on your game in the D league where professional chefs, trainers, etc are around to help; all while not having the silly practice/class restrictions.
How can anyone argue that option #1 is the best for the young man? It just isn't. In the past, the stigma of the D league was the only thing that brought marginal prospects back to college. That stigma is gone, and now so are they.