Well you do have use for it if you want to get rid of the arrows on your shortcut icons. It is the only way to do it unless you change the icon itself grafically - and that is even more complex and you'd need more than 1 program (TweakUI) to do that.
yoda - all tweakui does is make registry changes. So anything you can do with a tweaker you can do manually in the registry. Personally, I prefer the easy way. I have tweakui, x-setup and tweakxp on my system. Not sure why everyone doesn't have at least one (x-setup being the most comprehensive).