I don’t even know where to begin with this one because there’s a lot of issues I have with this, but I think the first major thing to address is that your idea of what the musical “wants” to be about is not actually accurate to what the musical (or the play it’s based on) is about.
It’s not about those things, it was a tragic, surrealist play published in the early 1890s as a criticism of society’s lack of proper education of children (both regarding the system of education as a whole, and education regarding sex) leading to tragedies such as Wendla’s rape and forced abortion which ultimately caused her death, and Moritz’s failure in school and lack of compassion by his teachers and parents, and the school system as a whole leading him to believe that, if he failed in school, he would have no future and thus have to take his own life.
Sater’s weird beliefs about Melchior aside, he’s also not actually the hero of the musical. He’s the primary protagonist, but he isn’t the hero and the story of Spring Awakening isn’t really the kind of story of clear cut heroes and villains anyways, but instead it’s just meant to be a series of vignettes for the audience to take however they want. The play was written to show how society had failed their kids and as a result caused the deaths of Moritz, Wendla, and numerous others who aren’t characters in the play/musical.
Also, the scene with the switch is supposed to be fucked up. Melchior, for all his knowledge gained from his uninhibited access to various kinds of books, is still a part of the same repressed society as the other children. That scene is the first one to really show Melchior losing control, that even though he seems to be well put-together up til that point, he has been equally harmed by the combination of the deeply repressive society of the time and his parents’ lack of involvement in the kind of information he has access to.
The whole point of Melchior’s and Wendla’s character arcs is the way that they have been equally failed by their parents and society in general, but in completely opposite ways, and that failure leads to what occurs between them. It isn’t meant to be a black or white moral issue of these individual children, but a commentary on the larger problems caused by their families, school, and the church that lead to Wendla’s rape/pregnancy/death.
And interpreting Moritz’s death as Melchior’s fault is just... objectively wrong. In fact, that’s exactly what the adults try to blame it on in order to shift the responsibility off of themselves. He isn’t even the reason Moritz “got into trouble in the first place,” because no one knew about Melchior’s letter until after Moritz died, and Moritz had already been failing his classes to begin with. His death wasn’t caused by exposure to knowledge of sex. Moritz’s death was caused by societal pressures from his family and teachers that were forcing him to work harder and harder at an impossible goal with no regard for his personal health, and permanently labeling him as a failure for not being able to accomplish it. His arc with Melchior’s letter is secondary, and again reflects the deeply repressed society that he lives in that he feels like a completely normal part of puberty is ruining his life, and he has no outlet to talk about it to anyone, nor does he even really know what he’s going through at all. If anything, Melchior was trying to help his friend because he thought gaining more knowledge would help him stop feeling so anxious over it.
And how is it Melchior’s fault that he didn’t go running to save Moritz before he died? The only person that Moritz told that he would commit suicide because of his situation was Frau Gabor, but she doesn’t take him seriously and we have no reason to assume that she would tell Melchior this. Within the context of the musical, we never even find out if Melchior knew that Moritz failed his exams--the last time they interact is when Moritz is telling everyone that he passed. He has no reason to assume what Moritz is doing just because he wasn’t at church with everyone else when he was hiding away at the hayloft.
Spring Awakening is not a story about sex positivity and owning your body. It’s a story about children that were horribly failed by the disinterested and unsympathetic adults that were meant to guide them, but only pushed them further into extreme tragedy. The musical is not trying to be edgy for edgy’s sake, it was written to appeal to teenagers who felt similarly unheard and misunderstood by the adults in their lives, and it’s unfortunate that the things criticized in the 19th century play are still issues to this day, considering how many people interpret Moritz’s suicide as being a result of corruption via sexual knowledge and not the adults who pushed him to extremes and then used a scapegoat for the blame, and focus solely on Melchior’s bad actions as if they’re an isolated case in a fictional story and not written intentionally to reflect society’s contribution to creating people who do the same things that he did.
