Although I agree 100% with your critique I disagree completely with UX being about triggering an emotional response.
I know UX people like to claim they are responsible for the user experience but this is really not true unless they are able to actually visually design the site too as the visual part is the primary emotional trigger.
This is why all UX people should be able to design.
The problem with his twitter redesign isn't about the emotional response but simply about the information design. It's badly done and reduces the ability to scan the page.
I think so too. It always confuses me when I see companies look for UX and UI as 2 separate things. The more layers of designers you introduce to the process, the more likely it is for the main concept to be lost in translation. I like Twitter's model where designers work together as an extension of a Creative Director with skills in UX/UI/Front-end.