Newsflash- VCs dont usually invest in hackathon companies, yes, they get invited all the time, they get to judge, sometimes angels/incubators might give you an invite, or an interview with a VC as a prize (the most bullshit prize) the cash prices (whatever amount they are are much better than VC money or VC time or etc....) If a VC is there, they're just filling time and seats and meeting some future people, but rarely companies. And I say this as a top 20 finalist on a 400 team nationwide weekend hackathon. VCs don't invest in hackathon companies, the offered prizes as VC money come with many, many caveats. Some angels maybe invest but its doubtful. Though yeah, agreed, it is all about the APIs, baby.
I had a decent experience at a recent hackathon. I sat down started coding, fell asleep about 0400, woke up, pointed at things like I had a clue what was going on. Sure the code was not anything to brag about, for me it was the socialization. Being able to talk development with others; hell I even learned a couple of things.