There is a school of thought that indicates if we attend to our own needs first, we are far more effective at attending to others needs
Yes, and as you sort of said, that's a two way thing: he might be better at interacting with her in the way she needs after he has alone time, but she also might be better at allowing him alone time after a period of her preferred interaction. If he gave her what she needed first, she might be able to give him alone time more "efficiently", without sitting there sighing and tapping her fingers. If she waited, he might genuinely give her the interaction she needs rather than sort of feigning it. All of that is totally true. You can just see from the way he phrased it that he thought her need was less important than his, less "right", because he views people who need that sort of thing as "wrong" for needing it.