His first example doesn't seem like a place where this is a good plan.
The person who takes joy in hurting others will not treat you well for letting him hurt you. They will only try harder to get a reaction.
More to the point, they will try hard on the next person. That person might be worse off than you. Less able to defend themselves.
So, no. Being nice is not the right thing in all cases. The best response to a bully is still to hit them where it hurts.