The approach is not without a foundation. Checkout the "Collections" menu here (for one example):
http://www.typography.com/
In both these cases the focus *needs* to stay on the links and not on the header/groupings. If anything can be improved here, it's the strength of the links, maybe.
I can toy with some additional colors for these headers, but we certainly shouldn't blog 1.8.0's release on this issue.
The choice was made deliberately.