That is a salient and good point. Vader baits Luke to Cloud City by torturing Han and Leia. He knows about Luke’s attachment to his friends. and Luke’s identity was that his father was a hero and jedi knight, that is shattered by the revelation Darth is his dad. By threatening to turn his sister Leia he incenses Luke to near patricide.

and we see him wearing black like Vader, choaking Gamorrean guards, threatening to murder Jabba. and even further in the throne room he looks at his father’s stump and looks at his own metal hand. he was becoming Vader. he was already on his way when he fought the shadow version of himself in the cave in TESB, that was a warning. What’s in there only what you take with you. Luke brought his fear and hatred into the cave. Fear and anger are of the dark side, so is impetuousness and impatience. Anakin has those traits. take the quick and easy path, become an agent of evil.

All your live have you looked away to the future, to the horizon. Never your mind on where you were, what you were doing, adventure, excitement a Jedi craves not these things.