If you mean for the main character's look it has little purpose. We have yet (nor do I think we will ever) to see the MC's face. Adding changes to the girls looks is ok due to how limited the scenes are involving their outfits. Clothing changes for them are visually the point for buying them in the first place. Don't like the outfits? Only buy what is needed from the PC. Changing the MC's appearance, let's say with the hair example you gave would mean almost every scene involving the MC would need 9 times the work. Plus, we would only see side profiles and obscured face images. Incredible idea with great examples just not for this game.