Cynicism is perceived as more intelligent [0]. I personally find the HN brand of discussion to be difficult to bs my way into. But no matter your level of competency you can always find something to criticize and feel you've contributed. I wonder if academia or even "more intelligent" discussion in general would be counted as more negative.
As someone who is not an academic myself, but likes to listen to podcasts where academics discuss issues with each other, I often find that the conversations feel contentious, and sometimes they are, but the vast majority of the time the academics themselves feel like they're having a perfectly cordial and productive conversation. So I do think there is something to the idea that academic discussion comes across as being negative.
https://journals.sagepub.com/doi/pdf/10.1177/014616721878319...