I notice I am confused. I do not agree with the statement "all websites should look clean and sparse" but I have also never once thought "this website is too clean-looking".
These seems at odds with each other.
Perhaps I have not explored the right part of the website layout continuum.
You may sometimes have failed to think (or feel) "this website is dynamic and exciting and intriguing" where you might have done so had its designers given more weight to other things besides cleanness and sparsity.
I've just launched WorldviewNaturalism.com, which is intended as a simple "landing page" to be used for introducing your friends to scientific naturalism. Many of the recommended readings linked there are written by LWers. Enjoy.
(This is a very old personal project on which I've spent a few hours per month, and it is not at all associated with the Singularity Institute or the Center for Applied Rationality.)