I often see those W3C buttons on the bottom of various pages that allow the viewer to confirm that the page was standards compliant. Being the see-to-believe kind of guy that I am, I do usually click those buttons, and it’s funny how many times the validation service returns a list of errors. I’m not going to claim that this page is fully compliant. It will generate many errors, in fact. But I do believe that standards are an important topic that designers often wrestle with and users ought to understand.
Specifications (I’m being very broad here) are important because it provides software developers a way to make sure their system behaves in a way that is consistent with expectations. Specifications improve the interoperability among software pieces, because each program knows what behavior to expect from other programs. In the context of web design, if products are not made to spec, that is, if browsers followed different rules when converting from code to what you see on the screen, then you get cases like MS Internet Explorer 6 or even IE7 not displaying the page in the same as say Firefox/Safari/Opera do. This makes for more work and frustration for web developers who subsequently have to develop hacks to accommodate half the online population who still use IE.
With brand loyalty, the bottom line, and/or reputation at stake, designers cannot then simply ignore half the population for the sake of this ivory-tower ideal. This is where user awareness is so important. If the majority of users abandoned less compliant browsers in favor of more compliant ones, then developers will have less incentive to spend their time hacking their code to work for the rare exception. Which means they can spend more time and effort on creative activities like graphical and interface design, which ultimately brings the benefit back to the users.