Because his agent would laugh in your face, that's why.
Yet if you look at his contract, he is getting seriously underpaid. I'm not sure if he will make a million dollars this year. (He was drafted in the sixth round I believe, and is playing under that contract) If I was Hardy, I would opt for a pay increase, and trust the big contract will come the next year. It should come the next year, if he has a fantastic year.