I have an expensive Miele dishwasher that is a little over 7 years old. The bottom rack is getting pretty rusty and I'm sure it costs a fortune to replace. The dishwasher has a built in water softener and I keep salt in it (Miele's very expensive brand) and the softener is adjusted to match the city water at my house.

My questions are:

Should I expect the bottom (and other) racks to last more than 7 years?

Am I doing something that causes the rusting to happen?

I tend to rinse all the dishes and pots before putting them in the dishwasher so there is not much stuff on them. I've heard that that can cause the dishwasher soap to attack things in the dishwasher (like silverware) since it has nothing else to do. Could the Cascade (powder) be attacking the dishwasher rack?