I think I agree with this. My friend Dave took a detour into cooking school in between startups, and used to talk about the difference between the NYC restaurant scene (he lived in Manhattan) and the Chicago scene, about how Chicago had a scene focused on building things up and being excited for new stuff to happen, and NYC had kind a vicious, competitive, cynical scene. I usually think of HN as an NYC-style scene, not a Chicago scene.

(I'm sure the phenomenon isn't unique to Chicago, but rather shared among all major cities that aren't NYC or LA).

But most of HN doesn't work in startups; something like half of it isn't in the US. Without explicit norms-setting that HN seems loathe to do, it's probably not reasonable to expect the kind of enthusiasm you're talking about.