In my personal opinion, receiving negative responses is good for your startup because learn to deal with them. I do agree, that if that is all you are getting, it is disconcerting. But, maybe there is something wrong with your startup/project.
Think about this, I have a lot of friends, and when I showed them my project, they all said: "That is amazing!" "It is going to change the world" So on, and so forth.
See I love my friends, but that doesn't help me. I am not building a startup to get fame, I am trying to solve a problem. My friends love me and don't want to hurt my feelings, but honestly, my feelings are not part of the startup equation. My friends will not help me improve my vision to solve a problem.
HN has been good at showing a lot of negatives when projects are shown here, but you have to really try to understand what they are saying. Listen to the negatives, they are the best response you are going to get, because they will highlight the flaws on your business model, your project or even your idea.
Instead of looking at those negative responses as a way to get you down, listen to them, and try to get the best out of it. Deep inside a negative is just another way to tell how to succeed.
Hope this helps,