If one lives in an area with snowy slush, etc., then I would tend not to cycle in my office clothing. I just can't afford time and more money to wear out my office clothing vs. cycling clothing (which tends to be sturdier materials anyway).

Best cycle commuting jacket for me: high visbility colours so that I can cycle safely in the dark, pit/underarm zippers if I need it, a jacket that's thick enough for days when the temperature drops well below freezing, plus a jacket that does not have back air vent. Those jackets are just too cold for me in the winter. (Fine in spring summer.)