I'm not so sure that the refrigerator magically stops bacteria. But...
Being a household full of teenagers, extended family, the occasional kid, and neighbors, running in and out... if I put a pizza in the fridge, I am just delaying throwing it away, because absolutely no one will touch it. The microwave at my house is only used to make popcorn, reheat coffee, and drying tobacco; absolutely nothing else goes into the thing, ever. But, if I leave the pizza on the counter, it magically disappears over night. If by some weird chance that pizza is left in the box when I wake up, I just eat it out of the box.
Being a household full of teenagers, extended family, the occasional kid, and neighbors, running in and out... if I put a pizza in the fridge, I am just delaying throwing it away, because absolutely no one will touch it. The microwave at my house is only used to make popcorn, reheat coffee, and drying tobacco; absolutely nothing else goes into the thing, ever. But, if I leave the pizza on the counter, it magically disappears over night. If by some weird chance that pizza is left in the box when I wake up, I just eat it out of the box.