Simplicity makes things harder. Pare away elements and what remains has less margin for error, and must be more effective. "Simplicity" isn't a license to put a couple of <li>'s and a <p> on a page and call it a day.

In your case, there is neither a grid nor a measure that makes the placement of elements on the page make sense. Text is haphazard. The "contents" of each section are stuffed into an inexplicable jQuery scroller. Nav elements are 18px and subheds are 14px; there is minimal contrast between elements. This probably wouldn't cut it as a blog template.

I like the restraint with color though. Color is one place where good-simple is easier than good-complex.

Department websites at universities are also probably not a good benchmark for your work. They tend to be utilitarian. Design is a secondary concern.