I'm not a recruiter, but I spend a lot of my time building up teams so I figure that makes me a de facto recruiter.

I've personally gone both extremes:

1. Spamming linkedin, message boards, etc.

2. Seeking out specific candidates, emailing them, offering to grab coffee or do a call.

I've had more success hiring with #2, in which regard I agree with the article. But it comes with a perverse side-effect: I am ignoring 95% of potential candidates, likely a similar group everyone else is ignoring. I am mostly contacting people with years of experience at good companies with a decent web presence. Because if I didn't, I wouldn't have time to do my other job duties. When I (or our internal technical recruiters) spam out a job we are giving more people a chance at the job, and are introducing fewer personal biases.

I'm not saying either approach is right or wrong, I just think there's room for both. Maybe the ultimate solution is a single centralized marketplace for jobs, but it doesn't seem like there's been a clear winner in this space.