Excellent article. On the whole, I agree. And I wish that I had listened less, when purchasing some of my domains, to outdated notions about keyword SEO value. All the same, I can envision a scenario when type-in traffic will make a resurgence. The lack of privacy on social networking sites like Facebook may provoke a backlash. But I'm also expecting businesses to realize -- once their honeymoon with social media is over -- that they have relinquished a large share of their own online brand presence to companies like Facebook. And those businesses could begin a mass exodus away from social media and toward a kind of online independence that might be strengthened by (and strengthen) type-in traffic.
If you look at DNS' sales over the past 6 months, you'll notice that a majority of them are brandables, with a few keyword generics thrown in. Schilling is the smartest domainer I know; he figured this out a long time back. He's very active in buying two word brandable names.
But at the same time, what you say holds true as well: by using social media, you are essentially giving away your brand presence to Facebook and Twitter. Ideally, your traffic strategy should be a mix of all sources - SEO, social media, and even paid.
What I mentioned, but didn't expand on in the article is that different kind of startups need different kind of traffic sources. Some, like Instagram, instantly lend themselves to social media. Others, like Mahalo or a real-estate startup, does not. These still need to rely on SEO. The thing that has changed is that in the past 3 years, there have been a lot more Instagrams and few Mahalos and eHows showing up on the startup scene, hence the slow devaluation of SEO focused keyword names.