Although I was bummed about not getting through to the next round - I DO NOT feel that I was hard done by. In fact, YC partners clearly thought that there were better businesses to back or a better fit.
... and that's OK. The best thing to do, is to focus more of your energy towards your own startup.
I do not believe any of the processes need to change - if they realise something is broken, YC's partners will adjust accordingly. After all, they are also in business to make money - so if they start picking bad businesses to back, then they will change their application process accordingly.
Life's never fair, so just get over it and hustler harder!