Elliot Rodgers "Retribution."
Unlike Dr. Phil, I cannot really claim the pretense that I can analyze and offer meaningful solutions to some one's problems after only a brief indirect encounter via telecommunications. From the video, however, Rodger appears frustrated over the fact that he has not been able to establish an emotionally satisfying relationship that, of course, includes sexual intercourse. (A fact, because he admits as much). And he appears embittered by the fantasy that everyone else does enjoy emotionally intimate relationships that include lots of sex. (A fantasy--because everyone else doesn't). So he sits around seething in anger while fantasizing about everyone else's sex life and the one he wishes to be his own.
There. That's my Dr. Phil moment.
A couple of additional observations.
First, Rodger appears confused over the difference between love and lust. Love--even erotic love--rests upon the idea of the well-being of the other person. In contrast, lust rests upon acquiring and possessing someone or something to fulfill one's own desires. Or to borrow a point from the philosopher Kant in another context, one involves treating a person as an end; the other involves treating a person as a means.
As Rodger keeps returning to sex--sex--sex in his retribution video, he gives the impression that sex preoccupied his mind rather than relationships. And maybe that's why he experienced failure in establishing relationships with women. They saw right though him that he possessed no sincere interest in them as persons, only as objects of his lust.
Second, he entertains a some strange notions of justice. The ancient and best definition of justice is "giving each person his due"--what is owed him. In Rodger's confused mind, what is owed him is sexual access to every woman's body. And what is owed others who deny Rodger his justice? Well, death of course.