You're right and the Giants are going to point to that for leverage on their side in the negotiations. Jacobs side will point to the fact he is one of 5 backs in NFL history to get 1000 yards in 10 games, and that his injuries were all freakish and he'll be able to sustain a larger workload and still be as effective.
Such is the art of the negotiation for a player.
When these guys sniff a big payday, they go after it. In this case I have no problem with it.