Because in Celsius, 0 lets you know the water outside will likely be frozen and 100 lets you know the water in your pot is likely boiling. This is utterly useless information.

It is nowhere near as useful day to day as knowing 0°F means a very specific saltwater brine mixture will likely be frozen, and 90°F is kind of as hot as your insides. Or 96. Or 98.6 as the third revision decided.

I find that increments of 1C are too small to be useful in daily life but increments of 5C are quite big. As a result, you can't really round degrees Celsius to a multiple of 5 whereas full precision integer temperatures are too precise. So for example 15C and 17C feel like different temperatures, but each 1C step from 15C to 16C to 17C is not really useful.

In contrast, it's very reasonable to round temperature to increments of 5 degrees Fahrenheit. So for example 58F and 60F are basically the same temperature as far as my perception is concerned.

1990s LCD HVAC thermostats that didn’t go down to half degrees had better precision when set to °F vs °C.

There's also this famous comparison chart meme: https://www.reddit.com/r/slatestarcodex/comments/t0lnjt/fahr...

...making the point that Fahrenheit's 0-100 range is better suited to normal day to day measurements than 0-100 Celsius. The numbers that feel easiest to communicate with are scaled nicely relative to the range of temperatures you most often want to communicate about.