If no 3-point shot is the issue, it's something he could always practice at the next level. I don't think it's the dealbreaker that something like slowness is when it comes to NBA executives. But I will add that it's ridiculous to draft a SF who can't hit a single three, and that talented SFs are a dime a dozen.
I personally think it would be better for his career if he grew an inch or two and worked out like a fiend.