Good point about Hartwell and Sharper. I also agree with you that Scott is probably the man out this offseason. However, Scott has been a great Raven and is extremely loyal. He is a great teammate, and unlike the other backers you mentioned, Scott adds to the intensity of our defense instead or merely feeding off of it. Scott himself has turned into a good leader, and I believe others play better with him around.
As for Scott being mediocre this season, I think he has played as big a part as anyone in the reason why our run defense and total is ranked #2 in the league. The sack numbers might not be there, but like others pointed out in this thread, he is not a pass rusher. He is a hard blitzer, which sacks at that point are a product of the scheme. More than anything though, Scott has been rocksolid against the run.