Plus it's not like the developers would be talking about something obscure, they would be talking about their core competencies.
Presenting yourself in a video might be a challenge:
* You are an introvert/shy guy
* Your written english is fine, but your accent sucks/you are not that fluent
Both (especially the first though) are really no big problems in a business relationship, especially for these kinds of projects. I'd even argue that number one is the stereotype of a potentially great hacker. So - letting guys like these compete in a video contest with people that are more self-confident/marketing savvy is 'discriminating' .
Plus I think the video would be a really big deal for first time solicitors for code projects.
Creating a video is the worst way to get an impression though, in my world. If you meet me on the street we can have a great talk and I am quite confident that my english is more than good (though with an accent that I hate) enough to discuss every practical matter. Doing a video call would be more awkward, but perfectly doable. Sitting alone in front of a camera, selling myself to the world with a broad smile? Nope, sir...
I don't think that I'm alone with that attitude and I doubt that this influences my communication skills in a project let alone my coding abilities.
For one $2000 project, people are going to want to see your face. For a $500,000 project, people are fine with email and phone.
Since this site seems to be an international offer I see the following counter points:
* Getting $2000 per day is ridiculously high for lots of people. Just think of eastern Europe & India, to name some obvious samples
* Paying $2000 might be a lot as well: Again, thinking on an international. If you live in a "poorer" place investing $2000 to get someone to create your idea might be more close to the $500,000 for your guys (those with $2000 per day have to work 250 days to get there. $2000 can be close to a yearly income depending on your place of work).
And in the end I don't understand that people want to offer remote jobs/telecommuting, but still want to talk face to face. But I understand that this is something a quite personal decision or preference, so maybe this is just to be expected for some people/clients.