The title might feel pompous.
After I add my motto; Never underestimate the stupidity of a human being - It surely sounds even worse.
My excuse is that I admit my stupidity also as a designer. We tend to overlook the challenges users have in their interaction with our designs. The issue is the same, the important thing is that we study the issue - what ever the point of view may be.
Demystifying Usability has some good thinking on How to deal with Stupid Users.
The main points to remember are:
1. Users who have trouble with designs and feel stupid lack
a key behavior required in using most interfaces: Discovery
2. Users who struggle with interfaces and feel of incompetent do not notice or use features.
3. Users who struggle with designs that do not feel intuitive are not
comfortable with interface elements that are too different.
4.Users who do not make interface design distinctions ignore complex or multi-step tasks.
5. Users that lack the confidence with
computers have a thinner comfort
barrier and a general helplessness.