Not a rant at all. It never made sense in any way a real person would accept; as seen in many a superhero film, there are some clearly lethal villains who cannot be captured, forced to stand down, surrender or leave. In situations of that kind, the villain has to be killed, otherwise the hero is playing with the lives of the innocent all to maintain his or her self-image related to an unworkable, largely irrational code. As seen in Captain America: The First Avenger, the final fight aboard the Valkyrie was in no way a mission to capture the Red Skull, who was intent on launching advanced bombs on populations around the world, potentially killing hundreds of millions of civilians. Knowing this, Cap was aboard to kill the Red Skull, not talk him down, or apprehend him. In Man of Steel, Zod was not going to listen to pleading, accept negotiation (not that there was any way to negotiate with a super-powered tyrant) when he launched the World Engine, or was set to murder a family. There's no tired grinning, winking to the camera and picking a villain up by the collar to hand him off the police. The same applies to Thanos. If a threat is to sell as a believable threat, the hero--on occasion--has to accept there are no options other than to eliminate the villain. Failing that, the innocent suffer to unimaginable degrees (especially with the plans and actions of the three named antagonists).