Will is part of his own situation... A lot of the reason things went down the way they did was because of how expensive he was... With out the crippling dead money he may have been traded by now to a team where he could have played DE for a few more years. He was so expensive that we had to find something for him to do...

As much as I think he is a genius, Will's contract was one of Loomis' dumber moments. FO should have cut/traded him before the big money years hit. Since they didn't, we got this situation on our hands

There are three separate costs associated with Will Smiths contract.

His base didnt explode until 2011.

Then there is the 2m roster bonus every year.

His dead money hit hasn't been below 7M since 2009 which is the year he had 13 sacks.

So by the time he was not preforming to his contract value it was too expensive to cut him due to Dead Money..

So in reality it has been cheaper to keep him and swallow the cap hit than to suffer the dead money escalation.

Reference
Will Smith Contracts, Salaries, Cap Hits, & Transactions

It was bad from the start but no one knew he wouldn't live up to expectations until it was too late.

Also at the time you had a good tandem with Grant which meant only one was getting a double team but then Grant went to crap which led to Smith drawing the double team which led to his lower numbers.