Unless a site is completely unnavigable, we don't care a whit about being optimized, fully HTML-compliant, or anything else like that. We don't look at HTML source code. Regular users don't; there's no need for us to, either. We're even pretty good at ignoring broken images (unless they're the meat of the content) and, frankly, we have listed plenty of extraordinarily ugly and poorly-constructed sites.
A site should be COMPLETE. Links should lead to pages with real content. The first whiff of "Under Construction" or similar text is usually a fast ticket to the directory dustbin.
It's all about the content. If the content is there and can be found with a reasonable amount of effort, that's all that's necessary. If there is no content, it doesn't matter what sitereportcard.com might say about a site; it's not listable. The ONLY time when poor design is a factor is when the design actually prevents the content from being viewable.