My impression is that lots of users have been so affected by frequent encounters of bad UI that they just internalized it as they're "bad at computers/technology" and become afraid of doing anything. Maybe they'll go read a book (on paper) or something.
Whatever they do, complaining about the bad UI to the people who might have done something about it isn't it.
When users raise an issue like this, I try to show empathy right away. I know they are already on edge thinking: "Am I the stupid one?" Of course, there are users with nothing but packing peanuts in their brains, but the good users with real brains... be good to them when they raise an issue!
I agree. The knee jerk reaction of many otherwise highly educated corporate users when there is a UI issue: "Oh, I must be doing something wrong." So often, something is wrong on the server that is causing horrible lag or weird errors.
It is more amazing when you meet a very resilient user (think: senior sales staff -- they'll do /anything/ for a sales commission!). They just assume this is normal operating procedure. Only when things are horrible, do they ask for help. Then, you stand behind their desk and watch in horror at all the bugs they workaround (many times per hour!) in your app, but never report... Hat tip to these amazing users!
Whatever they do, complaining about the bad UI to the people who might have done something about it isn't it.