We build websites following the standards created by the World Wide Web Consortium (W3C). Compliant sites make it easier for search engine spiders to evaluate the content on a page, which can help make your site indexed more accurately. Standards also allow your site to look and operate consistently among major web browsers and platforms.
An overlooked but important advantage to standards based web design is accessibility. This applies to people with impairments or disabilities that rely on alternative means of web browsing, such as those who use screen readers to interpret web pages.
The most important thing to remember in web design is that there is a lot more to your site than just how it looks. Some websites sacrifice usability for aesthetics. Others have great content but poor design. When we build a site, we pay close attention to every part of it. No single element is too mundane or irrelevant.
In the end, we need to reach a balance between design, functionality and usability. If one of those areas fails, then the site fails.