Some say that Sarah's actions in T2 caused John's death? That's hilariously stupid.
The direct result of destroying Cyberdyne was that SkyNet never existed in the future thus no war and instead a new A.I would take over.
But it wasn't Sarah's actions that killed John, nor was it Legions own doing. What killed John was a T800 sent back by SkyNet before Cyberdyne was even destroyed.
So ignore ppl who say that it was the price Sarah pays for destroying Cyberdyne - that's drama bullshit and most likely hype to further drill into us how "Terminator has always been Sarah's story" which is also bullshit.
John was killed due to shitty writing and that's it. Had Sarah and Co. never destroyed Cyberdyne, then that T800 still would have terminated John at the beach bar if that was his true fate. And we all know what his true fate is: to survive and lead humanity against the machines.