Because having someone else buy a gun for you that you can’t legally buy, traveling to a confrontational hotspot with your guns, failing to leave a situation that was escalating, and that choice leading to one shooting a mentally ill bipolar person is perfectly legal. And the right wing absolutely wants to make sure everyone knows that. So he gets to be trotted out for any occasion where they need a “famous” person who chose to exercise their right to self-defense, despite making every effort to place themselves in a situation where it might be necessary.
But that’s not his fault.