Just like shocks dampen the bumps in the road.... because your suspension is actually messed up and the shocks just mask it. I know what worked to fix mine... I thought I could leave it out, based on what I had read in various forums, and be great with all new components. So I tried it and found it would oscillate quite a bit.
In my rebuild I replaced the entire steering linkage, ball joints, etc. and had the alignment checked, tires ballanced, and had an oscillation when I first got it out on the road without the SS. I put in the SS and the problem went away. If you say it masks it, then I agree in the sense that masking it equates to stopping the DW oscillation from starting. The SS is a designed part of the system, which was engineered as a whole working unit. Remove a piece and it may work for some, but not for others depending on cumulative in/out tolerences of the system.
-I am not trying to argue, we are all trying to help accomplish the same goal to help the OP