Quote Originally Posted by Vyrerus View Post
It does shield the Earth though, at least partially, and that is the direct reason for why it has craters. No meteorites hitting it = no craters
That's not because it's "shielding the Earth" though; it's because both Earth and Moon are both objects in space that can potentially get hit by space rocks coming in from any direction. One wears all its scars forever on a rocky surface, the other hides them and wears them down or swallows them in the ocean without a mark to be seen.

Things might be aimed at the Earth but hit the Moon first. But just as possible they might come from the opposite direction and hit the larger Earth first.

Additionally, despite the "lunar cataclysm" description of the Late Heavy Bombardment theory you linked, as far as I can tell the only reason it's called "lunar" is because that's where the (debated) evidence for it is found. The article talks about it bombarding all four terrestrial planets and has a whole section on how Earth would have been impacted by it, with no mention of the idea of the Moon shielding it from anything.

Again, look at the size of the Moon in the night sky. That is how much of the Earth's surface it can shield at any given point, and the other half of the globe is completely unprotected.