The fault is the person who made the user interface. A
screenshot should be grayed out or somehow distinguishable from
the rest of the UI - or should be clickable. Think about it: If
multiple users are having the same problem, the problem isn't
the users: the app/program/interface has usability issues.
Usability testing should always take place using real people
rather than people who are embedded in the system and already
know it. Blaming the user is a common IT blunder.