In canon, the love shield requires more than just not fighting back- the person who dies needs to have a choice between death and life, and to intend to die. (When Harry died in the Battle of Hogwarts, he didn't fight back, made the choice to die earlier, and willingly went to his death.) The love shield only applied to Harry because Lily was explicitly given the choice to step aside and live, and chose not to take it; James' death didn't create a love shield around Lily because Voldemort never gave him the option to live, and so James wasn't able to explicitly choose death.
While canon doesn't really show this, I doubt many other dark lords would have given their victims' defenders a choice between life and death. (Also, IIRC, at the end of canon, the Love Shield still wasn't widely known.)
PS. If the Love Shield does exist in MoR, do you suppose Bellatrix could cast it?
If Love Shields really do work the way Randaly describes, then I think the odds of one being used to protect a Dark Wizard are at least as high as one being to protect someone from him. Scenario: Dark Wizard and Obsessed Minion (e.g. Voldemort and Bella) are cornered by Aurors, who explicitly state that anyone who surrenders will be taken alive, only for the Minion to willfully choose to take a lethal curse for her master.
(And somewhere in the back of his mind was a small, small note of confusion, a sense of something wrong about that story; and it should have been a part of Harry's art to notice that tiny note, but he was distracted. For it is a sad rule that whenever you are most in need of your art as a rationalist, that is when you are most likely to forget it.)
Why does the wizarding world believe Voldemort used the Killing Curse on Harry? Whether or not the Love Shield exists in MoR, I doubt most wizards had an >epsilon prior for the Killing Curse resulting in a scarred but otherwise unharmed target, a dead and burned spellcaster, and a destroyed building. There were no surviving witnesses except Baby Harry. Where did that version of events come from?
If I was Joe Random Wizard and heard that evidence without names attached, I would naively hypothesize: Dark Wizard shows up at house, encounters mother + father + their allies. Battle ensues. Parents and Dark Wizard are slain. House is destroyed and baby is hit by debris. There is one obvious question - why the allies didn't take the baby with them - but any answer to that is more plausible than "There were no allies; the most reliable curse in the world backfired on its most experienced practitioner."
Not that the "reflected curse" story was hard to sell. People are great at not asking the next question when they want to believe.
We have some additional information about the events of that evening:
What really happened at Godric's Hollow?
PS. If the Love Shield does exist in MoR, do you suppose Bellatrix could cast it?