I don't agree with you. I am a Giants fan, and he didn't do anything to blow us up. Well, unless you consider his recommending that one of his assistants take over, and that assistant turned out to be horrible. I think you will find that most Giants fans hold Tuna in very high regard.
And he seems to have left the Jets in pretty good shape.
He did seem to hold some animosity towards the Patriots though, there is no question.