because human beings create models, and human beings are more or less influenced ( but always are some way, some how ...) by the existential connection to their sensible surroundings.
lot of words to say ... cold and snow is their primary ongoing risks ( or used to be ...) so some how, some way, that influences the way they construct their environmental tooling that is charged with the responsibility of predicting threats.
it's not a directive ... more of an indirect bias, hugely subtle.