Peoples opinions are just that, opinions. Typically used to stir up buzz and media. The truth of SEO is this, as long as there are search engines, it is always relevant and needed. Search engines run on algorithms and this means that they are looking for certain things. Search engine optimization helps the bots and crawlers find those certain things.
People are free to think SEO is dead. While you are thinking that, your competition is passing you by at a fast pace.