"... community should have a default position of supporting entrepreneurship (and, more generally, of supporting attempts to build anything) --- and, that should be a norm."

I disagree and find such a community engineering approach dangerous for the health of the very community it's trying to "save". I think there are two big problems with it: (i) It gives too much power to the gatekeeper(s), be it software or human, and (ii) it creates a bias for positive comments.

This is the typical dilemma: Bad comments and a free forum are two sides of the same coin. Although I hate snarky, nonconstructive comments as much as everybody else, I think that trying to curtail one may also damage HN's innovative and free atmosphere, which is its main asset.