Nice thing about basketball is that you can't hide your faults.
Either you have the ability to get separation, or you don't. At the end of a close game, it's almost always the two best players on the court going head-to-head. It's not the Pinch Hitter who's the 23rd guy off the bench. Or a QB of a team with a strong defense who has to do *just* enough to get into FG range. Or a relief pitcher with that uncanny ability to get balls hit at guys. There's just way less "luck" involved with being successful in the NBA.
Lin has shown the ability to consistently get separation, get to the hoop and find his teammates. Sure, he'll struggle eventually. But in basketball more than any other sport, the "tools" translate. If you got it, you got it. He could should shoot 4-18 and score 11 points but still help his team with a half-dozen assists and all the things a point guard can do to make his teammates better.
He's not the next CP3 or anything, but I don't see why he can't be a consistent 15 and 8 guy for a few years. Plenty of value in that.
-chef