In this Mexican stand-off, with 3 years left on his contract, he needs to get his ass into camp. His value--this year--is declining with each practice missed.
There's no comparing an NFL contract to a real-life contract. The owners in the NFL have an out: they can cut a player at any time for any reason and not have to pay the player's salary. The player's leverage is the renegotiation after a good year. Again, no problem with Peters demanding a renegotiation--but he needs to do it from inside camp, not from his home.