Why are unscented after-shave so uncommon, most of after-shave I can find at a reasonable price have that typical cheap cologne smell which is going to wreck any perfume you wear.
But when looking in most shop, most of them still have some fragance in-it and often, so looks like that people shaving their face buy-it
Tax reasons perhaps? In some countries ethanol with (certain kinds of) perfume mix can be taxed as denatured alcohol, otherwise some other kind of denaturant would be needed