The insight here is valuable with regards of early research of markup languages, and where is has intercepted with the history of the Web, and what the academic community was trying to achieve.
Obviously, the later quarrels between supporters of XHTML v.s. HTML5, and W3C v.s. WHATWG was epic, yet it’s important that new technologies are always built on top of the old, no matter how “uncool” the old technologies we think they are.
I hope there are more interviews like this documenting the later history of the Web markup technologies.