SEO is not a myth, there are indeed things that you can control to impress a computer based algorithm directly or indirectly. Google is proactively seeking ways to limit how much influence a webmaster can have on the rankings however as long as there is a computer algorithm weighing signals there will be SEO.
Just don't forget about the human factor because no matter how much the search company touts their algorithms they fall back on human evaluators more heavily than they will ever admit.
Netmeg is right, if you're good at your craft business will find you. The better SEO firms will also find you. If you can't beat em, sign em up.