It has nothing to do with simping, it has to do with understanding the context of the manga, and the feelings of the characters involved. And no, I havent read the novel.
Actually, you know what, lets say you are right, I am simping for the MC, so why is my position called “simping”, and yours for Yuki is called… what? Not simping? The true explanation?
And no, if he had gone claiming to everyone what had happened, what would the others say “he is lying, that didnt happen, he is just bitter we banished him”, as typical scum would do. Yuki would believe him but what would happen afterwards?
As I said, lack of understanding of what is happening and the characters.