First, I realize that there is often value in standards.
However, I have an extreme distaste when people run around and try to label everything that does not fit in the tiny little restricted world view of the standard committee as "wrong."
Web designers whose pages do not validate DHMTL strict are neither writing "wrong" nor "bad" code.
The real definition of quirk mode is simply: quirk mode is the default DTD. It is the DTD used when a page does not specify a DTD, or when the HTML code in the document does not match the specified DTD. For example, you will go into quirk mode when you forget the closing slash on an image tag, or when you use an align=center attribute in the p tag of the paragraph you want to center.
The only "wrong" code that is written occurs when a person specifies a DTD and does not follow it. Designers who chose to do all their work in the default (quirk) mode are neither writing bad nor wrong HTML. For that matter, they really aren't writing "non-standard" HTML, as their HTML follows the rules of the de facto Netscape 4 standard.
Yes, I realize that commissars reject the existence of de facto standards. Commissars are likely to say that standards can't evolve. Standards have to be dictated by small minds. The W3C has many of the smallest minds in the industry.
For the most parts standard committees are just another playing field where megacorporations battle eachother for dominance. The company that can get the most of its design methodology scribed in the standard wins.
Standards can provide value, but they do so in a strange way. A standards committee stops evolution on one level. Often this lets us innovate on other levels. More often than not, standards simply stop the evolution of ideas.
The effects of standards committee are not always good. The industry should always be free to accept or reject non-critical standards.
My experience is that it is easy for a human to sit down and pound out quirk mode HTML in notepad. Quirk mode is much more organic. It is much more difficult for a human to write code in standards mode. Generally, the only way to get good DHTML strict code is to buy a compliant editor and validator from one of the megacorporations that had their hand in setting the standards.
Sorry about the terse reply, but people who use the default DTD are not wrong. They are not bad people. I prefer them to those who get anal about standards. The W3C calls the default DTD "quirk mode" because it has a nice little implied insult.
If the new standards really are not providing web designers anything of value, then the standards themselves need to evolve.