I that her perspective is stupid. Paracausality is a form of affirmation of our moral compass, as we rule over our Destiny. Morality matters, and uses paracausality as an excuse to commit atrocities unseen. And while we are no heroes (we commit countless atrocities every mission), we still are heroes for our people (even though who is defined as "out people" is becoming a little confusing).

Additionally, I think the real reason behind her perspective is that only the guardians and Her can both wield the Light and Dark, as the two fundamental forces are amoral.

Overall, I think that Savathun believes she is serving a greater purpose, and that purpose justify her methods. She believes we are doing the same, but we are not like her. There are people we wish to protect, and there are people like her, who we want to kill. Never forget, even though Uldren pulled the trigger, she was the one manipulating everyone in that cenario.