And without a reliable measure, they cannot have a concept that is valid. The very definitions of ESP talent were too muddy. Humans make an observation and infer an underlying ability. We observe a person predict an event without apparently using ordinary senses. We make an error when we believe that two events are necessarily causally related but are merely close in time.
Human memory is reconstructed.
Human motivation is such that we want to believe in magic, in something special. It makes life exciting or makes those who have this capacity special. Those are very rewarding feelings to have. But nice feelings don't make extrasensory perception real.