I think it's incredibly generous of anyone to call Langford underrated OR a mystery.
If anyone feels that way... They should be the person Danny Ainge calls up to offer the trade to.
The Jury is in on Langford: he's soft, injury prone, and doesn't have a jumpshot. Trade him for whatever value you can get before anyone else realizes this is who he really is.
Soft he is not. Kid tore ligaments in his wrist early in his college season. Despite many top prospects looking for a way to respectfully take the college season off, he continued gutting it out every game, leading his team in minutes, delaying surgery until after the draft, likely costing himself draft position and money, and certainly costing himself part of his rookie season. Then, in the bubble, he again suffered an injury that he knew would require surgery, but he continued playing until he suffered a second, unrelated injury. He will play through pain, and play through contact. He's not soft -- in fact, if he were soft, he might be less injury-prone.
Can't argue with injury prone -- hopefully it's bad luck, but only time will tell. If you want to say someone doesn't have a jumpshot based on 30-40 attempts in his rookie season, I can't stop you, but that seems like a hasty conclusion, at best. I'm sure you've watched them all 10 times over and can identify every unfixable flaw.