I'll make this brief.
David Andersen can do one thing effectively: hit the turnaround jump shot. He is amazing at it. But that's it. Literally, there's nothing else.
Andersen was never going to find time with Luis Scola, Patrick Patterson, Brad Miller and Chuck Hayes in tow. His absence gives the Rockets more roster flexibility (could add a third PG to the 15-man roster?) and earns them a second-round pick as a bonus. We've seen what the Rockets can do with those.
Simple move, but a nice one.