Matt Cutts says good content is more important than SEO.
There is actually a lot of truth to that. The problem is that too many people don't understand the definition of good content. This goes double if it's content you've produced. Nobody likes to hear that their baby is ugly.
But that's the thing. People will take this video (or the writing of pundits who will selectively extract what they want from it) and misconstrue Matt's message, deciding to avoid SEO and instead crank out content. Gobs and gobs of content. Much of that content will be unfocused, poorly formatted and have no sense of what query intent it is supposed to fulfill.
Then these same people will wonder why they're not getting a lot of Google love.
The Truth Doesn't Matter
What Matt says in this video is true, but the truth doesn't matter. Because it's how people interpret and execute on this information that will ultimately make the difference. Sadly, most won't do a good enough job. I might not be making many friends with that statement but I call them like I see them.
It's the same reason why I dislike the stern advice people give to 'write for people'. The problem? Most don't really know how to do that effectively. Instead, I tell people to write for search engines. The result? People write better content for people and, by extension, for search engines.
A good SEO serves as a guide to help you to both produce and get the most out of content, ensuring that it is valuable and satisfies query intent.