For over forty years now, Luke Skywalker has become nothing short of a legend and an icon, as well as a hero to so many people young and old, as has his awesome portrayer Mark Hamill. Throughout the Star Wars franchise, he is a beacon of light and hope and has become even more layered, but also divisive with the sequels, in the end still retaining his hero status.
Nevertheless, Luke is far from perfect and often heralded as one of the most annoying protagonists of all time. There are some aspects of Luke's life and personality that take a long while to fix, continuing to get worse and worse as the time progresses.
Physical Harm
Physical harm, scarring, burns, dismemberment, and flesh wounds are prominent throughout all of Star Wars, in every medium, every trilogy, and every story.
Luke Skywalker suffers this quite a bit in the original trilogy, not only did Mark Hamill's real-life unfortunate car crash lead to a Wampa attack scene but he also, in the same movie gets his hand cut off. When it gets replaced with a mechanical hand, that hand gets shot and scarred in the next film. The character and story are not worsened, just Luke's physical condition.
His Crush On Leia
One of the worst things from a narrative point of view to come out of Star Wars becoming the phenomenon it was, was Luke's schoolboy crush on Leia.
Overall, fans are glad the two are siblings, it adds a lot to the relationships and stories, but the kiss between the two, Luke's cocky reaction to the kiss and his overall increasing crush on Leia never aged well.
Never Focusing On The Moment
Qui-Gon Jinn famously veered away from the Jedi Council's ideology. He instead allowed the Living Force to be his authority. Qui-Gon was critical of how the Jedi often failed to focus on the moment, the instincts; instead, they looked to the future. Fast forward many decades, Yoda criticized Luke for the same thing.
Luke is a dreamer, and his whole life has dreamt of the stars of life off Tatooine. But, even when he gets off the sandy rock, he still looks to the future, to the horizon, taking a long time to finally become one with the moment itself, rather than the moments ahead.
Impatience
Tying in with Luke's inability to focus on the moment is his impatience. However, the difference is Luke's impatience gets in the way on a far more practical level, while his look to the future hurts his connection to the Force, to life.
Yoda lifting the X-wing from the swamp of Dagobah, alongside one of the greatest monologues in Star Wars, is the epitome of this, with Luke's impatience when training is evident. It is not until the final movie of the trilogy where Luke finally finds maturity and patience.
"No, I Am Your Father."
To the fans, when looking in on this Galaxy, this franchise, the incredible reveal that Luke Skywalker is the son of Darth Vader, is extraordinary and fantastic.
Luke struggled with it, though; it deeply affected him for a while in-between The Empire Strikes Back and Return Of The Jedi. It is hardly easy to find out you are the offspring of the most feared and evil figure in the Galaxy.
His Failure Of Ben
Jumping on two trilogies later to the sequels, one of the singular moments in which Luke instantly becomes worse is when he fails his nephew Ben Solo.
While Kylo's telling of the story is a lie or at the very least a manipulated memory in that Luke did not attack Kylo, he thought about it; for a split second, he thought about it and ignited his blade.
The Whining
Famously, Luke is an unbelievably whiny hero. This whininess eventually ceases, but it is one of the most prominent and pointed to criticisms of Luke, no matter how beloved he is.
The more time fans spend with Luke in A New Hope, the many more moments of pure and utter childish moaning fans get. This then continues through to Empire in his training with Yoda. All-in-all, it only serves to aid his arc and is great in that sense.
His Turn From Optimistic To Pessimistic
Luke is a ball of hope and light in the original trilogy, with deep-running emotion to him that must get tamed, and comes out in occasional bursts such as his momentary relentless attack on Vader. Through all of this, though, he retains his hope, his optimism, and his goodheartedness.
Fast forward to the sequels; Luke is a war hero, a legend, has traveled the Galaxy learning about the Force, the Sith, the Jedi, the history, and has become far more pessimistic. He believes the Jedi should end, that there is no good worthy enough in himself, and has lost a lot of the hope he once wore on his sleeve. It is a beautiful and understandable, if not controversial, and widely despised story that gets partly opposed in the next film.
His Growing Loose Relationship With The Truth
Another trait Luke seems to have developed by the time of the sequels is an Obi-Wan-esque relationship with the truth, but seemingly in a more obvious way.
While Obi-Wan was correct from an interpretive standpoint that Vader killed Anakin, but Luke telling Rey a wrong telling of events of what happened with Ben is a blatant lie. Another lie that is yet unexplored in canon - and so may not be a lie as such - is that Luke claims he does not know Rey but does know who she is - a Palpatine - in The Rise Of Skywalker.
Going Into Isolation
Of course, many of these points have an overarching issue, that being the worst thing Luke has ever done, both in Galaxy and from a creative standpoint to a pocket of fans, going into isolation.
Luke lost hope; he gave up, he was beaten up emotionally and mentally from all the events of the Galactic Civil War and the rising evil in the Galaxy. He snapped like a twig for a split second when he got scared, and he ran. An understandable decision from a human standpoint, and one that when Luke gets over, create an epic series of moments.