How hard is it to add c or f to the end of a tempreture
How the hell are people supposed to know if you are using celsius or fahrenheit
I see you’re Canadian so I can understand your frustrations (I wish the US would go metric personally) and I agree that if there is a chance of confusion, defaulting to being more specific is always correct. I’d say generalizing this to a situation where absolutely everyone else is also using mixed standards is not correct either.
There are also a lot of places in the world where you can be making small talk with a stranger about the weather and how nice a day it is at 22 today and both parties would understand the statement.
On the same vein of your last point, start talking about the weather that isn’t right at that second, now confusion can seep in.
“Today is nice at 22, but man back home it was -10 last week.” “Oh thats right, that last one is Fahrenheit since that’s local to me. What’s that in Celsius?”