Exactly. It doesn't make two fucks what YC thinks of you, your company, or anything else. Just go win without them. Muster up a little outrage if that sort of thing helps you, be pissed for 30 minutes or so, then buckle down and start writing code, or whatever you need to do to move forward.

As a wise man once said:

Let me tell you something you already know. The world ain't all sunshine and rainbows. It's a very mean and nasty place, and I don't care how tough you are, it will beat you to your knees and keep you there permanently if you let it. You, me, or nobody is gonna hit as hard as life. But it ain't about how hard you hit. It's about how hard you can get hit and keep moving forward; how much you can take and keep moving forward. That's how winning is done! Now if you know what you're worth, then go out and get what you're worth, but you gotta be willing to take the hits, and not pointing fingers saying you ain't where you wanna be because of him, or her, or anybody.