Ok, I'll give you that in some form but you're still wrong. Save someone in ten years from now and negate all future problems still accomplishes the same thing. The basic rule is the closer the timeline is to zero the more important things become. If you are altering the present timeline or the near future timeline you still are destroying the further future timeline and replacing it so anything done in that further future timeline ceases to have ever actually happened.
Bishop did but erased that probability by the simple fact they were time jumping then returned to live in the present and affect change. Understand any precog that warns anyone of anything is a planet killer but also a planet birther. Whether they do it by their own hands or just with a word of advice the result is the same. So to revise things because you're hung up on small matters I will happily kill everyone in one hundred years to save a bunh of people in ten years because any change will still destroy and rebuild those hundred year people timeline anyway.
Look I get you don't dig bishop, find his actions harsh. I really do. They are harsh. But for time travelers I do see some differences between things or anyone that has seen or knows the future really. I don't think babies should be killed, but I would totally kill baby hitler, mao and stalin with my bare hands and be ok with it. That's just how I see things.