Also people just don't want to hear about it on HN when it is all over the media already
And you don't actually "hear" people discussing in threads you don't click on. I don't want to hear about Apple, ever, nothing they do or make interests me, or ever will. Yet I wouldn't dream of curtailing others discussing that stuff.
Look at all the comments here. If a story leads to the comments here, it almost always gets flagged to discourage further unproductive commentary