I mean, it says the temperature it has to reach. So hotter will get it there faster. I don’t generally buy frozen pizzas but when I do it’s for a party so inevitably I end up with a bunch of boxes that say to cook at different temperatures. I heat the oven to 425, put them all in and remove as they finish (I have 2 ovens and 5 oven racks)

I do agree they should advise a temperature, you are right. But maybe more people are like me and disregard it?