That's the solution. You don't want to be recorded? Attend "no-recording" event. If there are no such events, tough luck. Market is not obligated to serve your particular needs. If you thing enough people care, organize it yourself.
Let's assume it's true. What does it mean? That pretending to ruthlessly murder people while not being recorded is a niche kink and society doesn't owe this guy any special accomodations.
Thanks to the internet, which publishing prowess he abhors, I'm sure, this guy will still be able to find group of fellow degenerates so he can have fun with his exact perversion down to a T.
Or he can relax his requirements and perhaps attend swingers club instead of airsoft, because they don't usually record their hobby. Or keep doing pretend murders but relax his stance about recording it towards more mainstream sensibilities.
Is this sufficient engagement with the topic for you?
Or do I have to spell out that privacy is not special. You aren't organically owed anything when you are with other people, except for what current societal sensibilities dictate.
I think for airsoft a facemask and pseudonym will do so you don't even need to invent anything, just apply it.
Do you think they hoped their blog post would have the force of law? I think the many conversations started on the front page of HN were probably more than sufficient impact. You _really_ don't need to be so defensive of the status quo.