The only feedback you need is from your customers--everything else is just bullshit and navel-gazing. Unless pg or sama is going to cut your company a check (and your rejection suggests that they won't), their approval or acceptance shouldn't matter to you one iota. That you didn't get into YC doesn't matter, and doesn't reflect poorly on you or your business.
no sane developer would trade his idea he spent several months working on for just 15k, even if it's YC. That's not how investor's market is right now.
Get back to work. :)