I am not in a position to doubt your stated preference, but certainly "it looks rather good to me" does not block you from understanding why others would would want some basic styles applied to the sites they create and visit.
The OP demo looks better only because the css adds a linebreak after the widgets. But I actually prefer the cleaner look of the default style. A matter of being used to it, probably.
I am not in a position to doubt your stated preference, but certainly "it looks rather good to me" does not block you from understanding why others would would want some basic styles applied to the sites they create and visit.