Potentially less than 50/50. The "entrepreneur" gets $1k, the rest of the resources have to split the other $1k. Doesn't seem that fair to me

Pairing an 'entrepreneur' with a developer can work, and I know of cases where the 'idea guy' deserves 50% - they tackle the market and sell the product. But in a Hackathon environment I'm not sure it would work: you have to share the same passion. It takes someone who has the insight and ability to push forward a really great product in an industry in which they completely understand, and a development partner who is completely engaged in wanting to implement this technology (or ideally, you both come from the same place). Is a weekend enough time to spark this kind of connection?

An "idea guy" who also handles marketing and sales shouldn't be considered just an "idea guy".

I completely agree but I feel there is a bias on HN towards non-technical founders, certainly under these conditions. I think it's important to understand what traits of a non-tech co-founders are going to be more valuable / interesting to work with: I've seen friends get stuck in bad positions because the founder can't grow a business (I've been in this place myself when young).