Ball is sort of the antithesis to those two guys though since he does shot well enough in college.  His shot can go in, it's just that it takes so long to get off and comes from such a low position, scouts don't think he'll be able to on a consistent basis unless he pushes out even farther.  Basically they don't know how well he'll do initiating an offense from 28-32 feet versus 23-7 feet.  That's a big difference.  
Of course, all the other guys besides maybe Fultz have warts as well.  Jackson's shot is iffy, Tatum's shot is slow and he tends to settle for long 2s (both big no-no's for SFs in today's NBA), Smith is erratic, Markkanen doesn't really have a position since he can't guard anyone, Fox's shot has problems, Monk has trouble with size as Jackson showed yesterday.  It's tough to know how much is this just nit-picking after bad NCAA tourney performances (ie small sample sizes) and how much of it long-term NBA issues.  This is especially true of all the PGs since running the PnR is so critical these days and besides for Fultz none of them have really shown they can do it consistently.  I won't be surprised if the 2-6 positions in the draft are different in June than they are now.