What you fail to mention...
Lets analyse something here...
"Chris Wilson, platform architect for Microsoft's Internet Explorer, has stated that while Acid 3 is "a collection of interesting tests," it is not Microsoft's goal to comply.
And don't all you open-source lot start tutting and muttering "typical Microsoft" either. Mozilla's Firefox 3 team has also dismissed Acid 3 saying: "None of the issues on the Acid 3 list are important enough.""
Lets run a couple of comparisons on whose implementing what eh?
Mozilla Firefox 3.0.1 scores a fairly respectable 71. In this case, Firefox can fairly comfortably sit the claim that the remaining tests are nothing to worry about, being as they are, mostly limited to things that most people will never encounter.
MSIE on the other hand...
Well. Its difficult to tell, as it doesn't even render the page nearly correctly. MSIE7 shows a jumbled mess. If I read it right, I think it scored a disastrous 12.
Now however you look at it, when a browser can't handle 4/5 of the web standards, you have to ask questions. Perhaps Chris WIlson would care to compare for himself and see how MSIE is not a web browser? (I'd say at least 3/5 is needed to qualify as a web browser).
P.S. For further comparison, Google Chrome scored 78. IIRC Safari/Windows scored similar, along with Opera achieving a respectable 84. Kinda makes "12 is OK really" look like a crap statement.