Usability vs Branding? - Usability is Branding

I've been in the following scenario several times. I'm in a meeting room with the web and marketing teams and there is a raging debate about brand guidelines. A proposed improvement to the design contravenes the guidelines. One group think that branding is more important than usability. The other group think the opposite. They are both wrong. Usability is branding. It shapes people's opinions of your product or organisation.

User Vision (2008). Articles>Usability>Branding>Web Design