Nothing about Kadary is NBA quality. In some ways that is why he was an attractive college player, he was never going anywere.
Most importantly and obviously, he can't shoot, and there just isn't a place in the NBA for a guard who can't shoot, unless you're a Westbrook type best athlete in the world. Kadary doesn'thave hops, and he's really slow by NBA guard standards.
He was great defensively in the zone but not as good man to man. Every coach he has had since high school complained publicly about his lack of a motor.
He's got size and he can pass, but you have to be really really good to be the guy who handles the ball all the time on an NBA team, and Kadary isn't useful off the ball because he can't shoot.