If Graham was so great for the offense, (and I think he was when not over-used), why do you think Payton didn't try harder to replace him in FA or the draft? There were some great TE in the draft the past few years, and players like Cook rarely come on the market.
i think re-tooling/shoring up defense was main priority - we could "get by" with a Watson for a few seasons while we get that squared away would be my guess.