The guy didn't compare to hamlet, he talked about the timlessness of some stories and how they are re-worked over time he then expanded on that point to then express his ideas for potential story expansion. Some people hate NTR due to their visceral reaction to a married partner cheating and betrayal. The female character in this story, does the same thing that we all do when we cross a moral line (cognitive dissonance), she rationalises that if only Felix did this, thought that, had a bigger this did more of this and less of that. She has been seduced by passion for a world she has not experienced, but ultimately her narrative shows that her moral boundary is moving and her rationlisations are to keep her mentally happy. Ulimately she is cheating and wants it all, tries to justify that she loves Felix, but ultimately deep down knows that if he finds out he will be mentally bereft, she is his world, Zack is slowly becoming her world and yet she is just another notch on Zachs bedpost. You can see how this is a constant rich NTR vein to mine, betrayal at the most basic level of a fundamental contract of fidelity (marriage).