As the author said: "A good arguer has to speak to and be heard by those with whom they disagree. This requires that they know the alternative views in the ways that those who hold those alternative views know them."

The people you perceive as emotional think they're holding their own beliefs for logical reasons. Maybe they're angry or annoyed because you're violating some deeply held principle of theirs, or misunderstanding their position, or seemingly accusing them of something - but from their perspective, the emotions will be reasonable, too.

Bad faith is rarer than people think, but it does happen (e.g. knowing your opponent is right about something specific, but pretending otherwise so you can "win"; or suspecting you're wrong about something but flinching away from any thought or evidence that would confirm it). Those are genuine cases of "emotional rather than logical". Even then, understanding the true details of the position your opponents hold and how they arrived there can only help you, not hurt you. The urge to "retaliate" with bad faith of your own should be ignored, because your perception is almost certainly biased to see bad faith where there isn't any. Bulverism (investigating your opponent's motives instead of the argument itself, using that to explain why they're wrong) needs to be used carefully or not at all - it's easy to do, it's often actually correct, but it harms your arguments a lot if you're wrong but helps very little if you're right, so it's not worth it.