> When I think about where explicit temperatures are needed in the home, the oven and thermostat are the two things that come to mind.

But in that case in what way is for example baking a frozen pizza from the store at 400 to 425 degrees F more relatable/convenient/natural than 200 to 220 degrees C?

It's not. When it comes to an oven, F and C are equally arbitrary, so it really doesn't matter. Optimize for what people use most, and let the other random uses fall as they may.