It takes a lot of time and energy to create and maintain a "beautiful" fake appearance, and it usually shows in personal development.
A stereotypical "fake" woman allocates a lot of resources on: regular hair/nail appointments, working out, tanning, plastic surgery and recovery, buying clothes, etc. This is in addition to an intense daily ritual of remaking herself with cosmetics. The same applies to men, albeit to a somewhat lesser extent in many cases.
The amount of time spent on these activities leaves less for the things that make people interesting and unique such as hobbies or intellectual pursuits.
Also, most people who place priority on their appearance seem to rely heavily on it when dealing with others. If they're already attractive ("fake" in this case), it's easier to make friends and get dates, whereas those who are deemed conventionally unattractive often develop other skills that help them to relate to people. Thus the "ugly" ones are the funniest, or the smartest, or the most talented in some respect compared to their fake counterparts.
Of course there are exceptions, but conventionally unattractive people are generally much more interesting and have better-developed personalities than fake ones. I'd go for "ugly".