At age 28 with the season he has had surprised he opted not to go to free agency. He should still get a contract. Should have been worth the risk.
But, to each their own.
Maybe he does... but what happens if he doesn't? You're talking about turning down a contract that will quadruple your net worth on a chance he gets what... the same thing? Something marginally better? Something worse? He could take that chance, and very easily be left holding his ball, and being forced to accept a much smaller contract. Remember Vokoun when he was looking for his big home run contract back in what... 2010? Didn't get it and ended up signing a 1 yr 1.5m deal with Washington. And Vokoun prior to that had earned millions (~25/30m?). Dell doesn't have that luxury to fall back on.
After this contract... yeah I could see him being pickier about where he signs and what his chances are with whomever he signs in regards to a shot at a starter role (or at least challenging for said spot). But right now? Financially it makes much more sense to grab that guaranteed money and run all the way to the bank.