So, as I mentioned elsewhere, Netflix is messing up Saint Seiya. The known SPECIFIC way they're doing this is by changing Andromeda Shun from a boy to a girl.
Now the question is "Why does this matter?", and there's more than one answer to that.
The general answer is: because Andromeda Shun's POINT was that he was able to be a man while having many standard feminine traits (being willing to show emotions other than anger or triumph, being very pretty, having a delicate face and figure, etc.), and who was even specifically representing a constellation which is female in its very imagery (Andromeda, chained to the rock). Shun was, in fact, one of, if not the very first, Bishonen Heroes, as far as I can tell (there were earlier bishonen, and earlier heroes, but I can't recall an earlier anime hero who was specifically a bishonen). Changing Shun to a girl eradicates the very point of his portrayal; he goes from a character who is genderqueer to a fairly traditional female who just happens to also be on a combat team.
Some people have pointed out that they did the same thing with Pidge in Voltron and THAT didn't cause problems, but that's because (based on discussion with old Voltron fans) Pidge didn't have the counter-gender imagery as a core part of their identity; much of the confusion about Pidge's gender was due at least in part to the American VA. For Shun, it's a complete negation of what made him one of the most popular characters in Saint Seiya.
If they wanted more diversity, and specifically female representation, they could have changed LITERALLY ANY OTHER CHARACTER to female -- Seiya himself, Shiryu, Hyoga, Ikki -- and there'd been far less griping about it. Or they could choose to bring some of the EXISTING female characters -- Saori, Shaina, Marin -- forward and give them more screen time and agency. Instead, they chose the worst possible way to do it.
The more specific answer for ME is that Saint Seiya itself is a very, very important influence. I had moved on from WATCHING it a while back, because in terms of the "god-warrior" show subgenre there were other shows that did it better (because Kurumada himself seemed pretty much stuck in a single rut when it comes to plotline and character portrayal).
But when I first encountered it, Saint Seiya was *eye-opening*. It was one of the first anime that my then-girlfriend, later-wife, Kathleen showed me, and its serious and sometimes agonizing portrayal of the superhero concept, mixed with mangled Greco-Roman imagery and Japanese sensibilities, hit me like a freight train. At the time, Kathy was also heavily into Saint Seiya, and it became one of our strongly-shared fandoms, connected of course to our beginning romance, and we started running (sometimes extremely intense) games set in the world of the Saints (which we eventually expanded to include the Samurai Troopers and at the end DB/DBZ as well).
This led to us writing a HUGE volume of Saint Seiya fanfic, all set in that same universe, all connected into a single gigantic narrative. We never FINISHED it all, but the UNfinished pieces totaled well over a million words.
This wasn't just important *personally*, as part of the formative time of our relationship, however. It was CRITICAL to my professional (in terms of being a writer) development. Working with Kathleen taught me pretty much everything I KNOW about writing characters. If anyone likes any of my characters AS PEOPLE, well, credit Kathleen and Saint Seiya. It was during the writing of one of those fics that I finally figured out what my villain Virigar truly was, and clarified my entire multiverse. There are numerous influences by Saint Seiya, directly or indirectly, through my writing; originally I had a very direct one, in that the warriors of Myrionar were not originally called "Justiciars" but "Saints", and Kyri then would have been The Phoenix Saint (which is Ikki's position in Saint Seiya). My current work, "Godswar" is a salute to Saint Seiya and the god-warrior subgenre as a whole in the same way that Grand Central Arena was a salute to Doc Smith and the space opera genre as a whole.
Therefore, messing up Saint Seiya has a PERSONAL impact that is, honestly, well out of proportion to how *good* the original show was. It was ... okay for its time, but plenty of other shows have done what it did better, sometimes FAR better. But none of them had, or COULD have, the same personal MEANING to me that Saint Seiya does, and thus tampering with some of the key elements of the show -- most especially Andromeda Shun -- is something that will REALLY bother me. After all, I spent quite a few years in the company of the Saints. Don't mess with my friends!