so common that it’s accepted as an excuse without question. Instead of allowing themselves to say, “this isn’t intuitive,” users may feel guilty, taking responsibility for that failure when the fault lies with the designer. “It isn’t intuitive,” isn’t a neat solution that removes the uncertainty, but blame is final.
I know that intuitive means "based on feelings rather than facts or proof"
"It's not intuitive" in the context of user-experience design refers to intuition:
...
4. the quality or ability of having such direct perception or quick insight.
...
Essentially, an experience being intuitive means that a user can walk up to the interface and immediately understand it.
The passage you quoted is describing the tendency of users to not admit difficulty understanding an interface, but it's pointing out that if a user has difficulty understanding it, it's really at the fault of the designer. Design should be easy to understand without too much digging--it should be "intuitive."
Another good term to describe an interface like that is "discoverable." In other words, users can discover features without having to read manuals or help documentation.
