I'm not quite sure how that's much of a hard choice. Users generally would browse request shops because they more than likely would contain examples of the artists work. All the user would have to do is a find an artist with a style that appealed to the him and make a request in the request thread. If the user couldn't find an artist with an appealing style, he could post in the requests board in hopes of finding a set that's right for him. It's not that hard of a decision. In fact, by removing the request shops, you will most likely discourage people from texturing if their textures are repeatedly being out beaten by the high end texture sets. A request shop often allowed an artist to become known and help him practice texturing.
In my opinion, by removing request shops, you have Hirt the texturing market as a whole.