In the early rounds, teams really draft on potential. They are looking at those guys who have all the measurables to excel. And very often, they find those guys who didn't really produce at the college level... but when they are developed, excel.
As they get into the later rounds, they start moving towards production. If a guy can produce, maybe he can't produce as highly as he didn't college, but he has qualities that lets him produce. Dax Milne has those qualities.
He already produces, and he's young enough that he still has the ability to grow. Some team is not going to want to risk not being able to attract him in free agency. Somebody will take a flyer on him.