I believe a common theme across many websites and software is the following:
Your website is chaotic, has too much content, and simply no organization or layout. It looks bad.
Your website is full of content, but still comprehensible. It is unique from the rest and looks good.
Your website is uses a off-the-shelf stylesheet. It isn’t that special, but nobody is going to judge you.
Your website tries to be innovate and strips out so much styling, that it is literally black on white paper. Some people might like it, but it’s boring.