The last few years have brought about many revivals and reboots of "intellectual properties" (IPs), such as Star Wars, Star Trek, Superman, Ghostbusters, and even She-Ra where the new creative teams have obvious philosophical/moral problems or disagreements with the original artwork.
While it may be legally and financially fine, commentating on another artists work while simultaneously appropriating their original ideas is morally wrong, just as a rich man who bought a culturally significant piece of art and then lit it on fire would rightly be judged harshly.
Let's take a look on why these "re-imagining" of properties, by other artists who have vastly different values and philosophies to the original works, is problematic.
Star Wars
With Star Wars: The Last Jedi Rian Johnson gave commentary on his apparent philosophical disagreement with relying on your own moral judgement and rather elevating the importance of submitting to legal authority. Also, suggesting it is better to bully and humiliate your enemies rather than to win them to your side with love and understanding. Rian banishes the Black and Asian characters to a pointless side story of failures and mistakes and instead focuses on a cowardly version of Luke Skywalker and developing a romance between the white female lead and the white villain who tortured her, killed her new friend (Han Solo), and repeatedly tried to kill her, just days earlier. That Johnson also made time to present the two female leaders of the rebellion as needlessly dictatorial and cruel to their comrade, and leader of their x-wing squadron so as to drive home the idea that it is more important to follow orders than save the lives of everyone aboard the ship is impressively "deconstructionist" of the humanist values of the original trilogy of films.
Star Trek
With Star Trek it has been Alex Kurtzman's disagreement with the original Star Trek concepts of intellectual and moral inspection by placing complex characters in unique situations to illustrate something about the human condition. Instead he seems to think that shouting, shooting, drinking, and stabbing are much cooler and less boring than all that silly science stuff. Like Johnson, Kurtzman constantly betrays the fact he, and his writers, have made almost zero effort to become familiar with the source material, with almost every episode of Star Trek: Picard misunderstanding a vital part of how the Star Trek universe works, and/or the history of the societies and characters in that universe. This laziness of something so easily correctable, and yet central to the very premise, betrays a disdain for the source material, as well as the audience.
Superman
With Superman, Zack Snyder it is rejection of the irony of a god-like being of physical perfection being an alien from another planet who must hide his true identity to save the ones he loves. Instead, Snyder's vision is of a pouting sullen god who sacrifices his own father to hide his true identity, and who gives into despair and violence when presented with a difficult moral dilemma. Snyder's Superman is a beautiful body and god-like powers, instead of a complex individual who must balance saving his friends and family while also protecting his city and adopted home planet.
Ghostbusters
With Ghostbusters it was less of a philosophical difference with the original work as a lazy retelling of the story with different gendered actors while squandering any interesting commentary on how a female perspective might have given the characters a different approach to their work. Was hiring a beautiful male idiot as their secretary, instead of the highly qualified, intelligent, and attractive female secretary of the original movie some statement on the sexism of the first movie having only male ghost busters? A more coherent script (supposedly a better draft exists before director, Paul Feig, altered the story).
Feig also chose not to have the female cast play the same characters from the original, instead, he had similar characters who just happened to be female. There was the loudmouth, the bumbling fool, the nerd, and the um... Black character? That these were not the same characters from the original, but completely new characters, made the choice to have (Black actor) Leslie Jones' character the only non-scientist of the group problematic, if not racist. Why are the races of the characters considered vital, but the genders are not? If there was no connection to the original movie, and the point of the movie was to make some statement about gender equality, an entirely original Specter Hunters movie would have been a more honest artistic statement. It is hard to defend the reason this movie was titled, Ghostbusters, except to sell Ghostbusters merchandise.
She-Ra
With She-Ra it was Noelle Stevenson's philosophical/moral disagreement with the portrayal of the original She-Ra as a 1980's personification of the perfect physical specimen of feminine beauty - big hair, short skirt, and high heels included. Instead her She-Ra was a flat chested teen with huge biceps. While the criticism that She-Ra's depiction of idealized female beauty was problematic is a perfectly valid argument (the same might also be said for He-Man, She-Ra's male counterpart), hijacking the original intellectual property to commentate on a moral/philosophical issue an artist has with the original work is inherently problematic. A more honest commentary would be to create a similar hero, perhaps named Her-Za, who embodied Stevenson's ideas about female power and served as a commentary and counter-argument to She-Ra's problematic ideas about the same topic.
Michelangelo's David
Imagine if I had a philosophical issue with the depiction of idealized male beauty in Michelangelo's David and instead of making my own statue illustrating the love-handles that any normal man's body would have, I made the same statue and called it a "long lost Michelangelo artwork" called David in Repose. Now even if I conceded, when pressed, that it wasn't actually a work of Michelangelo, but still marketed my statue to the general public as a Michelangelo sculpture I think it is pretty obvious that this would be immoral. Is it illegal? No. Michelangelo isn't around to sue me for it, but people would be understandably upset if they felt my work was dishonest and even that it may be insulting to Michelangelo.
The same can be said of the intellectual properties in popular culture that are given over to new artists to take a revisionist approach or antithetical philosophical direction. Commentary and critique of an artwork is inherently dishonest when presented under the "brand" or "IP" of the original work. While it may be perfectly legal to do so, it is morally wrong for another artist to usurp a body of work they did not create to deliver their own opposing views on the art. Not only is this dishonest in the way my example of the "new" David statue would be above, but it also stifles the creativity of a new artist to force them to work under the brand name of another artist's work.
Conclusion
It is perfectly fine for George Lucas to revise and re-edit his own works as much as he wants. While it may be upsetting to fans and historians, it is not an immoral decision. Star Wars was his creation. He can do with it whatever he wants. It is NOT the same thing for Rian Johnson to fundamentally alter the character of Luke Skywalker in order to tell his own story and deliver his own philosophical views on the futility of listening to the Force, especially when this is in direct opposition to the presented views in Lucas' original works.
It may be legally acceptable, but it should not be tolerated from an artistic and moral view. There is nothing stopping Johnson from making his own Space Battles movie about a mystical group of Gradzi warriors who use the mystical Anti-Entropy energy, and plasma blades, to fight the evil Interstellar Empire. The fact that it is more difficult to attract an audience to a new IP is not an excuse to commit the artistic forgery, and bait-and-switch marketing, of the companies and creators who attempt a "deconstruction" of another artist's works while selling it under the same name as the original.
