I think you're missing the whole point for "ShowHN", which IMHO is really valueable,worthy comments/opinions you should take into consideration.
Be respectful. Anyone sharing work is making a contribution, however modest.
Ask questions out of curiosity. Don't cross-examine.
Instead of "you're doing it wrong", suggest alternatives. When someone is learning, help them learn more.
When something isn't good, you needn't pretend that it is. But don't be gratuitously negative.
Calling someone's startup "headed for the deadpool" is the definition of gratuitously negative.