I can fully relate to your frustration. You spent time, money and extra effort on your pitch and YC could have told you straight away. It sometimes appears that Y has its particular business model anyway: basically an attractive and ready product in which they can invest at a very low price and then just take it by the hand, polish it a bit and introduce it to their contacts in order to get a good valuation through either funding or sale and hence a significant return on their investment. Nothing wrong with that as long as one realizes it. Maybe one should just copy that business model - as some have done already anyway.