As a guy who loves the natural look I can agree with you... and as an Assistant Photographer I saw the need for makeup. For some reason some normal faces and zits don't sell products. Everyone wants to dreams of something they don't have at some point. I have seen some beautiful natural girls that never needed makeup.. even in front of a camera! Of course I've seen the opposite too, where the natrual skin looked terrible on film.
As for the nails... I don't understand why girls want to pay for something that hinders ability and causes them to worry about breaking them, except to get attention! From a guys perspective... there are better ways!!!
Lastly, as long as people happily accept who they are... there's no need for makeup or nails!