One would think that after Endgame that things would be settled and the losses would be tallied and everyone would go on their way, but a theory that a certain god of thunder could have changed things around if not for his lone wolf tendencies is something that bears a bit of an explanation. The theory that Thor could have prevented Infinity War’s ending from being that much worse feels a bit pointless to talk about since not only does it indicate a desire for the Avengers to win and make the world safer, thereby ruining the overall story and its arc, but in the spirit of the theory, nor has to remember a few other key facts that affected the overall story. The fact that the theory seeks to cast blame on Thor is kind of juvenile in a way since if one is really going to say anything about this matter then we’d have to go a bit further back in MCU history to see what could have really been done to keep the team together and create a more unified front against a major villain. After all, Thor might be powerful, but at the end of the day, he’s still susceptible to various tricks and manipulative effects that work on others as well, as was proved when Wanda forced him to endure a hallucination that, much like the others, was able to waylay him just a bit.
But if we really want to put responsibility for the Age of Ultron on anyone, it has to be Tony Stark, since creating Ultron was one of the worst mistakes ever, while Thor’s aid in bringing Vision online was actually a way to balance this out since without Vision the Avengers might not have been able to save as many people, and Ultron could have potentially grown into an even greater threat. But let’s move forward and talk about how Sokovia was lifted from the earth, and how some think that Thor could have done more to help the situation if the boosters had been found quickly and disabled somehow. For one reason or another, Thor is being blamed for this as well since he was out doing what he’s best at, which is fighting off an enemy that doesn’t appear to stop. He’s not a genius like Stark and had no idea how to disable the boosters other than to destroy them, which might have caused more damage. His ‘lone wolf’ tendencies are what make him who he is, but his ability to work with a team is harder to deny than some might want to think, since despite his arrogance, which does show up sometimes, he has still developed throughout the course of the movies, and the character has matured in a very noticeable way as he’s learned how to rely on others and do what he can to help. But now we get to his appearance in Infinity War with Thanos, which has other moving parts that need to be addressed.
His absence during Civil War was probably for the best since it’s hard to say who he would have fought for, or if he would have shaken Tony and Steve like children until they found a way to resolve their differences. But Thor had his own problems at that time since he was trying to prevent Ragnarok from destroying his home, he had to find his father, and then he had to deal with losing Mjolnir thanks to his sister Hela. Taking on Thanos without a powerful weapon was obviously not a good idea since Thanos and his ‘children’ decimated Thor’s people during the beginning of Infinity War, which was hard to watch since it meant that, as usual, Thor had been severely stripped of a lot of power. But unfortunately, the loss of his people and the need for vengeance was too great when Thor finally showed up, after helping to craft a weapon that could take Thanos down. So the theory is kind of debunked again that his teamwork was lacking since to be certain, he was doing what he could for the team by helping to create a weapon that would be able to take the mad titan down. Given that he also needed to heal after taking more damage than many of the Avengers could hope to withstand, it wasn’t hard to figure out why Thor would show up in such dramatic fashion but a moment when things were just about at their worst. And also unfortunate was that his emotions were running too high and reason didn’t step in quick enough, since by wanting Thanos to suffer he allowed the snap to happen.
So there is definitely some blame to be put on Thor’s shoulders for how Infinity War ended, but to be realistic, he was doing his best, just like everyone else, all the way up to the snap.