This strongly depends on the personal taste of the creator.
As a possible workaround for you (if you don't allready know this):
You can use an alpha map texture to make clothing parts invisible.
If you are somewhat good in Photoshop or other painting tools, it is very easy.
Just search for the clothing texture or unzip it from the VAR file, then paint the parts to be transparent in solid black and everything else completely solid white. You will end with a very simple black and white picture with no details other than the two colors. Then open the clothes menu of the clothes item, go to where you can change the specific texture of the clothes part you want to edit and add your newly made alpha texture to the alpha texture slot. Ready.
As you may know, but maybe some other readers not: for many of the more complex clothes, you will have different textures for different parts organized in multiple tabs of the clothing item's menu. If you open one of this tabs where you can change the color etc, there is one slider for the alpha value. With that slider you can make those parts transparent or completely invisible.