As far as I can see, no-one seems to have touched on the one issue which may truly have effected Lucas more than any other.

He lost his mother in 1989 and his father in 1991.
Despite the differences he may have had with his parents, he seems to have remained very close to them until the their respective deaths.

That kind of experience is enough to re-calibrate anyone’s perception of life and it’s intrinsic values.

The prequels touched upon Anakin’s unwillingness to let Padme die.

Projecting himself onto/through Anakin, it could have been Lucas’s own way of his dealing with his pain…and the fact that he was unable to save his own parents…despite all his wealth and power.