Absolutely agree. The Lisp community could attract hundreds of new people overnight simply by learning a little CSS.
The one thing every other "hip and cool" language community has is that it has learnt that presentation matters. The people who use Python, Ruby and Node have all learnt this, but it seems most Common Lispers are perfectly happy with plain-old HTML pages that look like they were made in 1996.
I think that software deserves very minimal, functional and strict design. Accessibility over everything, uniformity over creativity. I "live" these design decisions for my business website and my products and I have attracted exactly the people I wanted to attract.
So I must assume that my 1996 design was the right choice for my customer segment.