DeAndre is gone, so no need to debate the Pro's & Con's of him staying any more. I appreciate what he contributed & he never complained one bit. No ill will.
Yes, DeAndre would have been a more featured player this year, with improved stats & a team leader, no doubt. However, he'll be 23 next April. NBA teams take that into account, along with body & determination, etc. He'd have to stand out like Bazz & A.Payne this past year, to get a 1st round pick next year. No guarantees.
That said, DeAndre's ticket to the NBA is the team that holds his rights. Right now, it's Toronto. They also drafted Bruno Caboclo (Brazil), another NBA SF, in the 1st round in 2014 (ie. Guaranteed Contract for at least 2-3 years). Bruno was supposed to be a "stash away" guy for 2 years (2 years away, from being 2 years away), but he made the Raptors, so DeAndre was stashed instead. Bruno has got a guaranteed contract, though he is only 19 years old (athletic, nice shooter, long, similar to D.D.). Also, Bruno is younger than D.Ham (Bruno turned 19 in Sept), hence the "potential" label. Toronto never has to sign DeAndre but can hold his rights forever, so that's not in DeAndre's favor. I don't think it's a great situation, unless there is an NBA who wants to trade for DeAndre, so it was almost better to be undrafted in that respect. I'd love to see an NBA team trade for DeAndre.... give him a real chance to make an NBA roster, instead of being "that stashed guy"... He's got NBA talent, he just needs the right fit. NBA teams love long, guys who can shoot. Who knows how this will end up? Best of Luck, DeAndre!