It's a very valid, believable and interesting presentation but when I see these things I get a sinking feeling in my stomach when I think of my own websites. This makes it look like I am doing lots of things wrong.
Funny thing is they don't seem to be much affected by all of these changes and have held consistently good positions since 2001 ;) so I won't be changing anything as a result of this.
I think this makes to look at in terms of aggregate factors that those interviewed believe are in play across a large number of genres.
Don't forget that the factors are likely a measurement across similar players in the same vertical.
For example, if you are not currently using diverse inbound marketing tactics, and nor are any competitors in your vertical (or their signal is not strong) then you may not notice any difference, and in fact could continue to rank well, even without (for example) social media.
So I believe these metrics are measured from competitors on a vertical and likely a query intention baseline.