Isaac messed up, but at the very least it is a mistake that he intentionally made.

I’ve said this before and I’ll say it again, Doorman is basically a guardian to Isaac and is trying to teach him, and especially to stop his dark thoughts.

See?? Look at this shit!!

Isaac was blaming himself, and doesn’t know why he is excluded, so he wants to improve himself, or better himself, but look at how he is literally going into shadows as he thinks about how he could improve himself.

And here comes Doorman to give the explanation of “maybe it isn’t your fault, but what had happened to you”. That kind of revelation could be the kick started to a long and happy life as an anime-villain.