Vulcans like order and neatness.When you think about it, it's really not...logical...that Vulcan men shave at all. It's a waste of time in the beginning of the day which could be put to better use.
Of course, Vulcan women wear makeup and outfits which go beyond mere functionality as well. So aesthetic preferences, while not governed by logic, must not be considered "emotion" by Vulcans.