Reheating Pizza in Microwave

Ok internets, you have failed my google search. So now I have to ask – why does the cheese in pizza reheated in the microwave taste so bad? There must be a scientist out there studying this. Just reheated two slices today in the oven. One warmed up fine and was tasty. The other needed some more heat so I popped it in the microwave. Big mistake. Like all reheated pizzas before it, the cheese turned into a disgusting layer that ruined the slice as a whole… Why???