You'd be surprised how often people would change things about their character if they could.
What I'm saying is many people change their appearance often in FFXIV because there's a lot of hairstyles, face paints and other options and you can come up with something unique every time. FFXIV just has a handful of hairstyles in two colors for each gender of each race, and small/medium/large size. That's it. People will only do it so many times because it won't take them that long to try everything.