With our YC application (we were rejected) we got x2 recommendations from previous YC founders, had other investors in this or the next round of funding, had an online demo, had users on said demo, and had a team of hackers/designers + various other things that we thought might add value to our application.
We didn't get in and have no idea why. The difference is our process was all part of our startup making a demo? networking with other founders? getting users?
I walked away from YC pondering why we were rejected, but reassured that we didn't waste our time - because most of the things we were going to do either way.
If I'd spent more than an hour talking to an investor I'd want a reason (and therefore value) as to why they walked away.