The difference is that waste heat from the engine appears outside of the clothes of our noise-propelled friends, whereas we cyclists have to carefully balance b

The difference is that waste heat from the engine appears outside of the clothes of our noise-propelled friends, whereas we cyclists have to carefully balance between isolation and cooling. If the route is hilly, you would actually want (but don't have) completely different sets of clothing for going up vs going down, on the same ride in the same weather conditions.