These are message boards. The obvious sentiment, that firebombing attacks are awful (perhaps cut a little bit with "the perpetrator appears to be someone deeply in need of help) is boring. This is an availability bias issue: the only sentiments that actually spool out into threads are edgy. Once you learn to spot these effects, message boards make a lot more sense and are less jarring.
I think this is a little too optimistic:
- Go onto a Reddit thread about ICE, everyone in the comment threads says they don't like ICE. That's the obvious statement, not edgy.
- Go onto a Reddit thread about Trump, everyone says they don't like Trump. That's the obvious statement, not edgy.
Why would we think the Sam Altman thread is any different? I unfortunately think the Reddit thread might be the real deal, or at least a little more real than you are saying.
And the same applies to HN? Edgy messages make it to the top, and the reader should learn to react accordingly (in what way?)
Another good thread to follow is the murdering of UnitedHealthcare CEO Brian Thompson: https://news.ycombinator.com/item?id=42317604
It's an interesting exercise to compare these threads.
My own position on the matter is the not an edgy one: political violence of any kind, is never justified, but it does signal that something deep in society requires a change.