I believe that is a choice for the owner(s) to make. It is their choice because of several reasons. Bandwidth, software or just the trouble to maintain the extra software it would create having multiple skins. On another forum I admin on we do have skin choices but there were financial considerations with supplying multiple skins also. bigc
We're not much into fancy styles and graphics, which is why the colors and icons are the vBulletin default and the Smilies match that color scheme. I'm not going to be adding any new skins here, at least not for the foreseeable future.