u/RedCaio

As Harry waves goodbye to Hogwarts and Hagrid waves back, the emotional music for Harry and his family plays softly at first and then crescendos into a majestic finale.

why so many Hogwarts tshirts? 1) no such thing as too much Hogwarts lol, 2) I was partially refining my vision 3) different angles and approaches

So to me "fixed points in time" are basically the writers saying "that's why the Doctor can't go back and stop all those Earth wars and tragedies the audience is familiar with" because otherwise it makes it seem like the Doctor doesn't care enough to stop them. And if he does stop them, "in this timeline the Doctor stopped Hitler" or something, it would feel almost disrespectful to the real people who suffered/died. So the show just says "those can't be prevented because ... we said so. just don't think about it, this show is just for fun after all".

Since fixed points in time all just feel like a flimsy "whatever" to me, I therefore view Waters of Mars "wrong", I don't have the takeaway the writers intended. The ep tries to portary the Doctor as "going too far" and being drunk with power, and we're mean to think, like captain Brooke, that the Doctor was wrong to save them. But in reality the future is always in flux, it depends on our choices here and now. Saving them was the right thing to do. The descendant can just get inspired some other way. Or someone else steps up in a similar way. Or something different entirely will happen. Sure the future would unfold differently then the Doctor remembers it, but that's fine. He rewrites the past on many occasions. Kazran from the Christmas Carol ep had his entire life and personality rewritten by the Doctor. The writers saying "but this time it's a fixed point so it's bad to save them" is arbitrary and boring to me.

Now if it were a paradox then that's fine. For example Star Trek: Strange New Worlds recently had a time travel ep where they end up way in the past and they had the chance to save the Martian race but at the last minute they withhold their help, allowing them to all die, because they realized a side effect of saving them would be that life never evolves on Earth which would erase the Enterprise from existence - it was a paradox. So they couldn't save them.

So if the show has said the Mars disaster somehow led to the Doctor's existence (I said somehow, lol, bare with me) then I'd be able to swallow being told he'd be wrong to save them. I guess I'm realizing at the end of this rant is that I find fixe points in time for real life events = fine, but fixed points for fictional ones = arbitrary and lazy unless there's like a paradox or some more compelling reason to say "can't intervene".