If we read the answers to this thread as a meta lesson of what a founder would expect, I think the answers would benefit from a scorecard. A poll at the top could summarise scores. Here is my iteration for the idea of "Apply YC":
1. Would I use this product? - Only for projects I have a lot of traction with and wouldn't mind competition for, or a project I am not sure/serious about (toss and see if it sticks). Anything in between would be risky if we're serious about the "What do you know that competition doesn't" question.
2. Would I join this team? - hard to learn about team without much research on HN
3. Would I fund/work on this problem? - Yes - a low friction way to vet and support startups is needed. I've worked on other iterations to find a way. I've thought about it a lot, reply/ping me if you want to discuss.
4. What would I improve: For start, add a scorecard, so the founders can use brainpower to iterate instead of trying to interpret why they were not up-voted by strangers with different motives.
5. Any concerns: A ton can go wrong here, but what matters is what can go right - what parts of the HN experience are conducive to solving this problem, and what tweaks will finish the job of solving it. If this works, you will see a rich data set of problems that people are attempting to solve, votes that show the demand for each problem, solutions who get to see traction by potential users, and VC analysts who are trying to crunch the data to direct their own funding/sourcing, competitors taking notes, etc.
Then there are also the projects that are just poor fit with the HN subset, would you reject those in YC if you see them down-voted here?