Pre heating became a thing when people started blindly following recipes instead of learn to cook by feel. Pre heating makes timing easier because if the recipe calls for 20 minutes at 350 you can start the timer as soon as you put your food in the oven. If you don't preheat you have to watch it closely and learn to tell when it's done.

What bothers me is that home teams will charge more for games against teams with big stars. If that star doesn't play because the coach wants to rest him you don't get a refund for the extra amount they charged you.