Help me understand the "HOLD OUT"

Bell said this before he turned down the 70M deal:

NY Times:
"I don’t play football just for money or things like that," Bell said. "I just want to be valued — whether it’s $15 million or lower or higher, whatever it is — I think we will get to an agreement eventually.”

But the highest paid running back in the league seems to still want more. Adrian Peterson still holds the highest paying contract for a running back in NFL history with his $96 million deal for seven years with Minnesota back in 2011, and it seems like Bell only cares about breaking that record right now despite making almost $4 million more per year than any other running back.

 

Of course it's true, everything on the internet is true.