I'd say its more likely to publicise that IE will handle css that other browsers will not. I have seen more than one web application that includes separate IE-only css files. (mostly to do with fancy tables and dhtml effects as I recall). Easy Toasty0, not everyone is out to get MS.
This is possibly an issue however as MS has the tendency to try and establish web standards as if it were the authority.
Note: both IE and Firefox fail miserably on my machine - neither even remotely resembles the reference rendering.
check the results of that test page here:
http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fwww.webstandards.org%2Fact%2Facid2%2Ftest.html%23top&usermedium=allhttp://jigsaw.w3.org/css-validator/http://www.w3.org/Note, that the page also uses png images which IE has never handled properly and still refuses to even with the promised improvements in IE7 (will still only handle 256 colors in images with transparencies... as if it were a gif). This one irks the hell out of me as it applies directly to my webmap which must use a directx alpha filter to display pngs properly in IE which adds a huge load on the client machine... Mozilla handles pngs properly natively with reasonable resource use. I'm not sure what MS has against pngs, I cant figure out why they won't handle them properly - I cant immediately think of a competing MS technology...