@jonsmth And none of that changes the fact that Kurt didn't care about his own best interests until his father flat-out told him, it's either you or MC. You can't cooperate. I won't allow it.
From my perspective, you're just making excuses. Even if all of that is true, and I'm not conceding that because you're just speculating and assuming intent, this is what we know for SURE, and what we know is that Kurt already tried to cooperate with whatever this protagonist is called because the translators can't settle on a name, he already pushed for this. And the father did a flat-no. The father created this situation. The father is the reason this is all happening. The father thinks it would "look bad" if Kurt and his younger adventurer brother cooperated to make the estate better for everyone, and shot down every attempt Kurt made to cooperate with his siblings, going out of his way to pit his children against each other.
The father is the villain of this arc, and if this goes the way the LN does, then he's going to get away with it while everything gets loaded off on Kurt. That's bad writing. If you want a character to be the villain, you have infinite freedom to write them in whatever way you want. This isn't good writing, it's lazy. We're being TOLD that Kurt is a bastard. That's not what we're being SHOWN. Good stories show. Bad stories and bad writing tell.