I guess the answer is that Rey must have more midichlorians.
No, the answer is: TFA is shit.
Great video. At 2:33, he partially confirms what I have been saying so far. Even though Luke was supposed to be a central part of the story and plot objective, the film goes on about completely unrelated crap. Instead of Luke’s disappearance driving the plot through gradually uncovering mastery behind his past decisions and actions, the film is a random collection of rehashed elements that does nothing for the plot.