Araragi getting together with Hanekawa while his feelings are mostly extreme gratitude and not romantic love will only end up in suffering for them both. He knew this, so he decided to not to pursue it. He already knew this when he realized that he wanted to die for Hanekawa, a feeling different from loving someone. You may choose to die for the person you love if necessary, but you don't want such a situation to arise. He did.

Araragi has always been a preachy idiotic asshole with no concern for other people's wills. That is why he got along so well with Hitagi, who is a more extreme version of him, without the idiocy.

Kizumonogatari should have been shown before Nise and this.