The reality is that when the Devils were going at their best, Hamilton was being used as a 3rd pairing D and PP1 guy, and the Devils need to spend their money wiser than that, even if Hamilton was crushing those minutes. When they had no injuries anywhere on the roster, it worked out great, but once any forwards started to falter, the cracks showed.
In a world where Luke's last name is not Hughes, the Devils could look into moving him for help up front and keeping Hamilton. But that's not the world we live in.