They mean it's not as precise or relatable as farenheit for talking about the weather. Like in farenheit 0 is cold and 100 is hot. Also more precise from one degree to the next. I just assumed that's what they mean from reading this topic many times before, but I don't agree with it, I can kind of understand, but the relatable part is just based on what you're used to, and the precision is moot, you can go after the decimal point in Celsius if you need further precision, which you really don't when talking about the weather anyway.
I have those kind of pants and a couple of shorts... I could use them but I lack confidense, altough I've been working out so my legs are in good shape at least.