Have a son who played in the NHL and he was told that because he was on the small  side he did not have to fight but just score goals. No pressure there.
Seriously though I have known many "heavyweights " and I have not come across one who liked fighting. Hockey players want to play not sit on the bench and have their feet freeze. Most players want to score goals or stop the puck. They'll say they like the hitting until they get smoked into the boards. 
Why do hockey players fight? For some they have to ,which sounds nuts until you put their situation into context. In today's game a dedicated fighter doesn't exist. Teams need 4 lines because the pace is so high even though most teams drop down to three lines when things get tense. 
Fighting in today's game is wrong. We know that past fighters used steroids and painkillers to get by. I saw guys so jacked up in the AHL you'd wonder what sport they were in. There's no testing in the AHL. Too expensive.