Thankfully its been awhile!I don't find people fighting entertaining in any way, so for me there's no such thing as a good fight.
Young guys shouldn't get into fights with old guys because no matter the outcome, the young guys can only look like jerks. Same thing with getting into fights with women, no matter the outcome you look like a jerk. Of course in many civilized areas it can be reasonably argued that you shouldn't get into a fight with anyone because no matter the outcome you look like a jerk. But hothead macho young guys can explode into violence over the dumbest things. Self control is another benefit of getting older.
People who treat animals badly usually also treat people badly. They're bullies. When you see bullying do you let it go or do you do something. Should the bully get away with bad behavior forever because no one stood up to him? I think it's easy to believe a good beatdown will teach a bully a lesson but more probably they don't change because they have some sort of psychological problem. The beatdown only makes them angrier but more cautious about who or when they bully.