I value quality in comments, which is one of the reasons I come to Hacker News. It is not a waste of my time. Reading comments on Facebook or any newspaper usually is.
Wikipedia isn't a waste either, mired in a Yahoo Answers low quality answers. That is why I donate.
Creating quality interaction isn't easy on the internet - I admire every success.
Shitposting in the comment-section of a newspaper or indeed Hacker News isn't "free speech", it is just disruptive and destructive.
When governments and corporations engage in bullshit (in the Harry Frankfurt sense) programs to disrupt public discourse, the answer isn't to yell and scream in the comment sections - that only helps them, in fact. The answer is to insist on solid arguments against their gish-gallops and red herrings.