I'm struggling to think of a common use case that makes heavy use of the "40-75C" range of the Celsius scale, and even for cooking you're mostly looking in the

I'm struggling to think of a common use case that makes heavy use of the "40-75C" range of the Celsius scale, and even for cooking you're mostly looking in the 150C-300C range, which is no more convenient than using 300-500F. There's no particular reason to be hung up on where water boils when it's not creating a particularly useful scale. You could just as easily set 100 to be the point at which proteins denature (~75C).