I have the same problem.  I see pictures of sheds with a perfect smooth packed floor like mine was when I started, now its a dusty mess 2" deep.  Skidloader destroys any packing in seconds.  I put some 1-1.5" clean rock down, it does help alot, but the skidloader still tears everything up.  I really didn't want to spend 15k for a concrete floor, but it looks better and better everyday.