The management is the one holding a grudge for something he did in the past. Not a lot of "turning the other cheek" for someone who you can bury into tasks and come back with reward.

Good management can de-escalate the situation and exploit his personality to work the system better. Not a lot of management Chess going on here, just people valuing feelings over making money. Not paying the guy the fair market worth for the work he did, isn't going to make him any more nice to work with.