Some reasons for whatever I was thinking about
:
1) Regular websites are composed using templates, copy and paste coding, and software applications that do it for us. Yahoo offers support for several file types and has made it generally easier for a user to set up a website, blog, message board, guestbook and a slew of other things. If you are looking at the PC side of the spectrum this is an accurate description.
2) Website Design is the careful process of testing compatibility with other browsers, determining a design or style for the client, designing the website so that it is easy to navigate. The latter is especially important for companies that offer a wide range of products. The website designer also has to decide if they will need to add some interactive components via Flash or Shockwave. It depends on the goal for the website.
3) Some Mac users are taking advantage of the newest addition, iWeb, to the iLife suite. They are taking their existing media and combining them to create good websites. PC users don't have an iLife

so their only option is to buy a Mac or get a life.
Website designers have 'hopefully' moved on to support Firefox, Netscape, Safari, and other standard compliant web browsers as well.
The problem I see is that Microsoft hasn't updated Internet Explorer for some time now. The only updates are for security almost every single day. When the company does change their browser they add frivilous features or steal coding and come up with an alternate name like J Script. I would say Internet Explorer is used by a significant majority of the population but unless you are a designer; one need not worry about supporting that old dog.