Ok, let me explain where I’m coming from.

The Jedi way is to forsake all forms of personal desires and wishes in favour of following the guiding will of the force. ‘The Jedi Path’ specifically states ‘the force has a plan for the galaxy’, Qui Gon told young Anakin that the Jedi quite their mind to hear the will of the force, the novel of revenge of the sith has Obi Wan tell Anakin that wanting to hold onto someone/something is to prioritise selfish desires ahead of the will of the force, which he says is not the Jedi way. All in all, I think we can agree the Jedi way is to follow the will of the force- ie. destiny- and such a way of life is how the Jedi devote themselves to the light side of the force.

The Sith, as we all know, is the opposite. They do not serve the will of the force- they serve their own will, even to the detriment of others. When Starkiller was asked if he could sense the future, he responded ’I’ve never been a Jedi before’ which implies Sith can’t sense the future as Jedi can. This would make sense- to sense the future, future events must already be predestined, which in Star Wars is another way of saying the force has already planned what’s going to happen. Having the force, or for that matter anyone/thing else, decide what the future holds rather than deciding for oneself goes against everything the Sith stand for.

I should also point out that all of this seems to suggest that fatalism is the way of the light side, while free will and self determination is the way of the dark side, but I digress. The point is, surely any use of the force which changes someone’s fate, such as using the power of the force to save someone from a death that actions not powered by the force cannot prevent, is to change the fate pre destined for that person, thereby going against the will of the force, which is the way of the dark side.