Why specifically would it be a good idea to design a phone that can get too hot to touch when you are in complete control of exactly what temperature it throttles at? Literally every single phone design team decides the hottest it should ever get and works backwards from there. This is a very standard step of the design of all hand-held hardware.

This isn't just some random thing that could occur on any phone given the right/wrong software. They very specifically make sure that the maximum theoretical temperature it could hit is still possible to hold in your hand. This is absolutely at the very least a firmware issue, but they don't want to change it because then the phone won't benchmark as well as it does now. So instead they are blaming software that runs the phone "too hard" rather than the phone being able to be run "too hard" in the first place.