He is going on his 14th season and he's going to be 35 in 2 months.
At some point he has to look in the mirror and ask himself how much longer he can play at top level because it was pretty obvious last season that he was already getting a lot slower and hardly playing at top level. He isnt playing a Kicker position where he can squeeze out a 20 year career like Jason Hanson, he plays a position that requires reaction time, speed and strength.
The smart thing would have been to take the $2M offer (which is even more than I would have paid for a slowing aging linebacker), realize its about the team and not himself, and reflect on his legacy as a respected Hall of Famer, instead of some Brett Favre type primadonna. If he signs with a division rival, he never again will be respected in a town where he spent 13 years building an amazing legacy. And all for what? a $4M or $6M salary for next 2 years instead of $2M? What does he think other teams will pay for him?