The article states that humans often don't mean what they say, but it goes deeper than semantics. It's not as if humans know exactly what they want every time

The article states that humans often don't mean what they say, but it goes deeper than semantics. It's not as if humans know exactly what they want every time but are frustrated in their attempts to express it. People often aren't really sure what they want in advance because they aren't sure what their options are. Mapping available options to outcomes and then ranking those outcomes is a non-trivial bit of computation that the human brain is performing all the time.