I agree that the basics are the most important part of anyone's game and that the ATs need to come later...but where's the understanding that different people learn things in different ways?
...if someone wants to learn DACUS so they can intelligently put it in their game, even if they can't always short hop their BAirs or their spacing isn't god like. I say let em, and stop telling them that there is only one way to properly learn the character. the basics are important, but some people thrive on their styles NOT being the basic styles, and who knows what those crazy people might find.
(I also want to go on record that I believe that DACUS is actually important to learn, or at least be able to pull off in a clutch. It's situational, and it may be difficult, but it's definitely has it's uses as a surprise attack and has yielded many a kill/wins for me. Not saying that it has to be the first thing learned...just saying that it shouldn't be shrugged off so quickly.)