Because, in all honesty, that's not that person's main job or they should have been fired long ago. I've played this game for a long time and tend to overlook the poor fashion choices at this stage, but with all the motif farming during the anniversary event, and the recent addition of the outfit system, it's disappointing that the majority of styles look like crap. My opinion, of course.
When I started playing, I thought the gear looked OK, but the more I leveled up, the more elaborate and ugly it became. Note to ZOS: Painting complicated patterns and ornaments on gear does not make it look good. Can we have something simple and elegant, please? I frequently end up coloring my gear in dark and uniform colors just to hide the ugliness beneath.
We can use low level gear in the outfit system of course, and that's OK, even though the choices that look half-way decent are limited there too. The problem, however, is that the textures of the racial styles are poor and low resolution compared to the later gear.
The coloring system is also a problem. Choosing a color does not guarantee it will look the same when you mix and match different styles. Also some colors are shiny, whereas others are not. Note #2 to ZOS: Fabric should look like fabric, and metal should look like metal. Take Khajiit light armor, for example. The level 1 gear looks OK, if a bit manky, but the higher level gear just adds a shine that makes it look like plastic. Add that many colors re-inforce the shininess of the material you apply them to, which they IMO should not, and you actually have relatively few choices for coloring your gear. Conversely I was very pleased to wear a Vet1-level (Calcinium) Breton heavy armor when I started playing the game long ago, before the coloring system. It was lovely, golden, and shiny, but that was only at Vet 1 to Vet 3. Later gear colors looked dull. Basically what I'm saying is that shininess should be a property of the material, not the color.
I am pleased with the character creator in this game. Not only does it allow you to tailor faces, but also body types. As far as the latter, it's actually much better than Skyrim. There are more parameters. It allowed me to create an overweight character with small breasts, for example. This brings me to another problem with the gear and costumes. They don't always respect the choices made in the character creator. One of the most egregious examples is the blue "Noble Dress" from the Crown Store, which makes your character much slimmer than they normally are. Conversely the Corseted Riding Outfit makes them look wide and cylinder-shaped, if you don't go for an overly slim waistline in the character creator. The point is: There is no consistency. My main character was designed to look good, if a little overweight, in the racial gear. She is also the only one who can wear the blue Noble Dress without looking anorexic. On the other hand, when Thieves Guild came along, the clothes were all really bulky.
What is it with the petal-shaped waist-line appendices in almost every style? I appreciate that this is part of the protection in a real-life knight's armor, but that doesn't mean every chest piece needs it. Clearly light armor derives it's protection from magic (shields), and medium armor from dodge rolling. I think ZOS got into a bit of a rut designing almost every style along those lines. It's become: Modify the shape of the petals slightly and paint something else on it. Where are the creative choices? Some of the low-level racial gear is useful simply because it doesn't have these appendages and thus allows for more unique-looking outfit design.
Gear stands and falls with the chest piece. Finally let me list some of the chest pieces that I actually think look good (on my female characters):
Nord heavy armor, level 1 and 2. Why is this the only chainmail in the game anyway? More chainmail, please!
Pact heavy armor
Xivkyn medium armor
Wood Elf jerkin and robe, level 4, if only it had better textures.
PC EU: Magblade (PvP main), DK (PvE Tank), Sorc (PvP and PvE), Magden (PvE Healer), Magplar (PvP and PvE DD), Arcanist (PvE DD)
PC NA: Magblade (PvP and PvE every role)