WaSP actually asked developers to learn about and use W3C recommendations, even if the resulting sites work less than optimally in broken, non-compliant browsers, and to inform their audience that better browsers are readily available and may be downloaded for free. How developers choose to implement these suggestions - if they choose to implement them at all - depends on the nature of each site and its audience. We expect that developers will analyze their audience and develop their own strategies and language.

Why do we encourage users (not developers) to upgrade their browsers? For the same reason Firestone encourages drivers to trade in unsafe tires. Previous browsers were not built to support CSS-1, HTML4/XHTML, ECMAScript, XML, and the DOM; the big two browsers, in particular, were built to compete with each other by any means necessary. Their focus was on proprietary technologies, and the market didn't tell them that standards were important. So support for standards in these browsers was often partial, often spotty, sometimes worse than no support at all. (It's better not to support CSS-1 than to support it so badly that websites crash.)

As a result of the way these old browsers were built, when developers follow W3C recommendations, the resulting sites can fail in these browsers. For instance, in 1999 I redesigned my (1995) online tutorial for web designers, replacing HTML table-based layouts with very basic, valid CSS-1. Netscape 4 users could not access this material without crashing. I used JavaScript to paste a warning message at the top of the page and stopped redesigning the site. My hands were tied.

Two years later, millions of Netscape 4 users still crash from basic, valid CSS-1. But Netscape has released a far more standards-compliant browser. As has Microsoft. As has Opera. There are other good ones as well. Continuing to rely on broken browsers is not a healthy long-term strategy for Web users. Ultimately all Web developers will build standards-compliant sites, and these users will be hurt. We're encouraging them to upgrade now, while most sites are still code tumors, so they can avoid being hurt.

Where can developers learn about W3C recommendations without getting a PhD?

Web Review has numerous articles working designers and developers can follow. A List Apart has a DOM series, a CSS series, and other articles anyone in the field can understand and use. We even try to make it entertaining, since learning new things can be daunting. There's good stuff at Web Reference, Webmonkey and Builder. Peter-Paul Koch runs a good DOM mailing list. Apple has good stuff.