You're right theoretically but I've seen numerous people on important FOSS and closed-source projects positions actually start addressing a problem after it has "gone viral" on HN.

Don't overestimate people; most devs and managers would look the other way if not much internet attention is given to their security issue. If they notice a report on HN they kind of panic and go in damage control mode, and then maybe actually fix the issue itself as well.

Being vocal on a popular and respected forum as HN is important for important issues to get much-needed attention.

Please note: I don't like that this is the truth but alas, I guess this is how Homo Sapiens works: it's not important if you know you screwed up; you can bullsh*t yourself to oblivion and delude your conscience but once many people know about your screw-up, then you suddenly care.