Answer:
Randy has the talk with Ponyboy because he wants all of the violence to stop.
Step-by-step explanation:
He was grieving over the loss of Bob, and he knew that fighting couldn't change anything. One side could show power over another, but no one would ever be equal. Randy wants to let Ponyboy know that he is a good person for helping the people in the fire, and that if he truly is, he would try to help stop the rumbles and such, too. At least, that's what I think.