[Macha]

100C is also very hot.

What's your standard of too hot? Uncomfortably hot? From the climate I'm used to then 80F qualifies. I'm not sure 80F is any less arbitrary a threshold than 25C. Don't confuse "my personal range of comfortable temperatures goes from 0-100F" with "0-100F maps neatly to every person's preferred temperature range and therefore is an advantage to fahrenheit"

(and that's before we get into the effects of humidity, or if outdoors, windspeed, on perception of temperature)

Similarly, 0F is -18C. -18C in my country would be a minor disaster, given our historical low is -5C. Our usual yearly low is about 0C, and 0C is more logical here than 32F, with negative temperatures actually being exceptional

[troad]

I’m honestly unsure how personal preference enters into it. For the vast majority of the planet, within an acceptable margin of error, 0 - 100 F will be a useful temperature range for almost all naturally occurring outside temperatures.

As for personal preference, I think the first two thirds of that range are unbearable. I grew up in an subtropical area that regularly rises over 100 F in the summer. I don’t go around pretending that’s not hot though. It’s very hot! Unless you’re proposing different temperature scales for every climate, I’m unsure how your point about your local area is relevant. Surely people travel outside of your (and my) warm climate.