Maybe the default HTML experience is, on its own, a good user-centered experience.
http://people.math.sc.edu/thornef/
Very simple static HTML. No stylesheet at all.
Although there are also a fair number of academics who invest more effort in web design than I do, this type of design is fairly common in math. I haven't heard anyone within the field criticize it as "bad" or "lazy".
For example, if I give a talk at a conference, then someone who was in the audience might plausibly look up my website to get a sense of my research interests.
I was thinking more of something like a CMS control panel or some data-entry tool, or a consumer website like an e-commerce.
The triumph of form over function.