I mentioned GUI as an example of an analogous domain where Google's strengths weren't necessarily of any advantage.

No, he did not. He mentioned GUIs in another part of his comment --and then went on to comment on the AI interface:

"""Google has shown us time and time again that big data isn't an advantage in creating graphical user interfaces. My sense is that the problems in an AI interface involve just as much design and interface expertise as they do data expertise""".