I don't see why we need a playmaker, or how that is even possible, at every position. Sometimes guys that go out there and do their job day in and day out are invaluable to the team. Yeah they might not get the fantasy stats, but they do their job. Clemons is that guy. He goes out there and gets everybody lined up. He doesn't allow many big plays, and he rarely makes mental mistakes. You don't just let a guy like that walk because you think that you might be able to maybe sign someone who can provide a big play every now and then, but lacks in the consistent play.
TL;DR Consistently above-average/good does not need to be upgraded when there are other holes to fill. If we are able to get a pro-bowl player at every other position, we can then upgrade Chris Clemons.