Snakes are just like people, some like it hot, and some don't. With that said, do everything in your power to set up his enclosure properly (i.e. identical hides on hot/cool side and proper temps on both sides of the tank) and your ball python will go where he knows he needs to go. This debate helps to confirm why we give our snakes a thermogradient. We provide them with the proper temperatures, but allow them a range of temperatures, so that they can pick what they want and deem necessary.

I have some breeder females that I have had for a number of years that do great, and I rarely if ever see on the hot side of their tub. They know what they need, and so long as you provide what is required, they will do fine.