Yup, we know...boy do we know. :) Rationally, and per our FAQ, we considered ditching it because the economics are marginal or worse. But neither Jose nor I could let the idea die. We hope the latest version hits the right combination of OK economics, and strong benefits for everyone involved.
We do it because we want it to exist. Getting past troubles in programming is much easier if you have people around, go for lunch, etc... who are pretty advanced. You are right that it's challenging to make it sustainable as a business. We are putting in serious hours (I'm fulltime on it since Nov 2013, and Kai is ramping up since he joined; he has his own clean energy startup to take care of too!). We do want Hacker Retreat to make meaningful money so it compensates the time invested, if anything. But this is no aim-for-the-moon startup.
Thanks! We think at least a few people from our last Fall batch would agree to that. We're intending more people to say that when this next session/batch is done.