If the germs are from the same air that you're breathing and moving around in, and not growing inside the dryer or particularly concentrated in any way, I don't

If the germs are from the same air that you're breathing and moving around in, and not growing inside the dryer or particularly concentrated in any way, I don't see what the problem is. The same germs will be found on the surface of paper towels or any other object in the bathroom. The article mentions attaching HEPA filters to hand dryers, but that sounds like a terrible idea since bathrooms are often humid. A wet filter quickly becomes a breeding ground for mold. If you really want to turn your hand dryer into an air sanitizer, how about ensuring that at some point during the air's passage through the machine, it reaches a temperature high enough to kill germs? (Cool it down a bit before it reaches the exhaust, of course.) Or maybe install a UVC lamp inside? These tricks will require a larger and much more expensive machine, though.