Putting aside the question of whether or not preserving the way the timeline is "supposed" to go is a worthy cause - not to mention the question of who, exactly, decides how things are supposed to go! - is murder really the only solution to free will oopsies? Can't they find some other way to put things back on track?
Actually make that two more thoughts - this show takes place in 2019, right? Something has gone very badly wrong with tech development in that universe, am I right?
Actually make that two more thoughts - this show takes place in 2019, right? Something has gone very badly wrong with tech development in that universe, am I right?