When people say this it always reminds me of a guy we had a few years back. A RB. Flashed a bit late in preseason games. Thought to myself...ah...good for him but he'll be out of the league next week. He's looking good against the other grocery clerks. Guy just kept playing. Next thing you know the fella actually had a spot on the team and made a former 1st rounder at his position expendable.
Point is, they have to start somewhere and some players use the opportunity to get their reps in, hone their craft a bit and make improvements. While it's easy to see a guy like Basham as a waste due to draft status, sometimes guys just take a bit longer.