I understood both sides during the Zeke contract negotiations.
On Zeke's side, he plays a position with a short shelf-life and that rarely sees big 2nd contracts. With slotted rookie contracts pretty much every other position gets a huge pay raise on that 2nd contract but it's a bit taboo to do that with RBs. So while other players get to cash in on their great seasons, teams generally don't want to reward RBs. Therefore I understood why he wanted to get paid sooner rather than later.
I think the Cowboys felt compelled to resign him because they invested a #4 draft pick in him. If Zeke were a mid-round draft pick I think they probably allow him to walk. I think most teams who spend that high of a draft pick on a Pro Bowl caliber player (which Zeke was at the time) would color outside some of their normal contract boundaries to sign that player to a 2nd contract. Regardless of the player's position. Kickers excluded obviously.