It's about as equally arbitrary as describing Celsius in terms of 101325 Pa ("standard pressure" boiling point).
Americans are more used to switching units and scales as they relate to the topic at hand. Describing distance between cities in inches is dumb. Using Celsius for the weather is equally unwieldy as the units are not fine grained and despite the headline, we're not even halfway to the boiling point of water on the Celsius scale. And likewise, if you live in a cold climate, even 0C isn't super relevant as a floor. Things don't even get uncomfortable until -10C anyway.
Speaking of Pascals, I feel "conversational" in Celsius and it kinda works but Pascals are even more irrelevant to daily tasks. Things don't even get interesting until you get to 200 kPa and jumps of less than 100kPa aren't very noteworthy. It's like currency after massive inflation.