I have never heard this for the all stainless All-Clad pieces (can't speak to Calphalon). In fact, their site states:
Is All-Clad dishwasher safe?
The ‘Stainless Steel’ collection is completely dishwasher-safe. It is recommended that before you use your Stainless Steel All-Clad you wash it in the dishwasher first to remove any manufacturing residues and this will help to keep it shiny. Do not put your non-stick cookware in the dishwasher because high heat and harsh detergents will corrode and dry out the surface. Copper-Core’ can be put in the dishwasher but it may result in some tarnishing of the copper band around the exterior. Prevent this by either hand-washing or drying the copper band immediately after the wash cycle in the dishwasher has finished. (
http://www.all-clad.com/Pages/Customer%20Service/faqs.aspx)
I have put most of mine in the dishwasher regularly for at least 15 years and have not had spots or any discoloration. To help with stuck-on food, or if I don't have time to soak, Bon Ami, Bar Keepers Friend or even plain baking soda all work wonders.