The trick is realizing the sponsors incentives -- they don't actually want the code you wrote in a weekend. If it's recruiting, they're looking for people to hire. If it's devrel, they're looking for people to sell their SaaS to.
They may not want the code, but they do want evidence that you can actually code. Hackathons are meant to find developers, not salespeople. So picking a team that didn't actually build something real as the winner seems like a rather bad idea.
Do you think they are out hunting powerpoint experts then?
Nah, but a developer who can sell is usually a better proposition than who cannot.
Really? I'll take the developer who actually makes things work.
If the developer cannot sell at all you won't really find him though.