One, "seeking work" as a freelancer doesn't necessarily mean the same thing as "unemployed". Many freelancers are juggling several projects, but still looking for few more to keep busy during the week. Some are looking for a future gig so that they have something to move on to next.
Two, the "developer shortage" you speak of tends to refer to full-time on-site developers. The people that fit these roles are not always the same as the people who are freelancers, often for lifestyle reasons. For example, not everyone wants to move to Palo Alto and work 60 hour weeks. Instead some choose the freelancing path because they have discovered that they can live more fulfilling lives by entirely avoiding the bureaucratic fascism of modern employment.
And finally, it's possible that the aforementioned "shortage" is the cause of a surplus in the other direction. It's easy to have ideas, and hard to implement them, so there are a lot of empty-shell startups springing up. These will have a hard time hiring good developers just because the developers have to be convinced of the value of this new hyper-social-geo-localized-dog-food-eating web service.
It might be interesting to know how many people actually got projects or jobs through this page. That would make it easier to benchmark my own listing.
For what it's worth, I don't believe there is any developer shortage at all, except maybe occasionally in unstable and hip niches.