Users judge a website or web application primarily on the design and usability of the site. It doesn't matter how well written and maintainable the underlying programming is if the site is ugly, slow, buggy, or counter-intuitive. The always spot on Jeffery Zeldman explains how we can all get to a world with better sites, better work, and better-informed clients.
It’s hard to understand web design when you don’t understand the web. And it’s hard to understand the web when those who are paid to explain it either don’t get it themselves, or are obliged for commercial reasons to suppress some of what they know, emphasizing the Barnumesque over the brilliant.