what is with the rant about excuses? Zemo believes the world is better off without superheroes, but the MCU just kinda...started having people say that without at all showing any really good reason for a rational person to believe it. It’s understandable that Zemo believes it, but he’s clearly wrong.
No, it isn't "clearly" wrong.
Zemo had his family killed by the actions of superheroes. Superheroes created a monster, and then countless people were hurt before they could stop it. That is something a rational person can look at and say, "Yeah, superheroes are a bad idea."
A rational person can also say that superheroes are a good idea, as they were required to save half the people in the universe... but that point is weakened by how poorly the world is managing their return, such that the return is not an unalloyed good.