Don't follow the instructions? food

I put it on at 220° Fahrenheit last time because I misread the instructions, and it cooked pretty much perfectly. This time, I follow the instructions and put one on at 425° and it burns heavily. What blithering idiot wrote these instructions? I even put on the second pizza for the minimum amount of time given on the box. I did that and what happened was a pizza that was burned on the bottom heavily, ok on the top, and cold in the middle.