When is comes to standards, the problem is a complicated one.
Designing for W3 standards (be it HTML or XHTML) is something easy if you train yourself to follow guidelines.
Why does it seem so difficult to implement?
In my experience there are many reasons.
You have so called web designers (basically a graphic artist) that are ignorant of the standards themselves. All their code is generated by Frontpage, Dreamweaver or some other WYSIWYG software. As long as the client accepts the final product they are happy.
Clients themselves are ignorant of the standards – so you can’t really fault them.
You do have certain clients that will insist that the site look good on their setup (usually a laptop with a high screen resolution), so they end up with a site catered to them, and no one else…
In the case of dynamic websites, you can often hand off W3 compliant templates to programmers. Now, many programmers don’t view HTML to be code, and,for lack of a better term, have no respect for the code. The programmer’s job is to get an application to work within their framework, as long as it displays okay, damn the standards…
Programmers have a way of over engineering applications and using a new technique because they want a challenge or be able to experiment. This is not to say that all web programmers are like that, just too many….
Finally you have the web browsers – they can have buggy implementations of the web standards or follow their own version. Now, even if you do follow “proper” HTML implementation, your displayed results can be different from browser to browser.
Another issue is one of design – to sell a web site, you often have to wow your client with a look at it may mean that you have to forego some standards for the “look”.
There is also a time factor involved in getting standards right. Ironically, Miss Hontebeyrie blog site has “done with error” on the link you have given(IE 6.0 on XP). Where does the problem lie in her case? Most likely with the software she is using. But I’m sure that almost all web surfers can read her site, so where is the incentive to correct her blog?
Standards in web design is a subject I’m keenly interested in and I’m sure we could comment for many more post.

Thanks for linking my post on francophone media. One small detail… I just picked up an analysis done by Benoit Bisson here: [url=http://blog-cafe.com/index.php/2005/03/22/93-medias-francophones-design-web-ouch]http://blog-cafe.com/index.php/2005/03/22/93-medias-francophones-design-web-ouch)[/url]

It was actually just the first part. Here’s the second part: [url=http://blog-cafe.com/index.php/2005/03/27/94-medias-francophones-et-standards-web-ouch]http://blog-cafe.com/index.php/2005/03/27/94-medias-francophones-et-standards-web-ouch[/url] … and it’s just as appauling!