Can someone explain to me why the front struts have to be cut to install the Konis? Is this because of the Koni design, or will every aftermarket shock require this?

I had planned on Konis and springs as the first mods when I get my '03, but I definitely hadn't planned on cutting the stock struts and adding Koni parts to create Frankenstruts. Will the full coilover kits from Tein be the same way?