I think you might be interpreting my point about SNR narrowly and literally, when I meant it in the broadest sense. Obviously social networks are not solely about exchanging information (which I never said...), they serve all sorts of other purposes, connecting and forming bonds being a major one.
I think you're also not being particularly charitable in your interpretations of what I'm saying, or opening yourself up to the possibility for other ways things can operate. If you were to be, you'd find we have quite a bit of agreement about this. Total signal also matters, good point I can see how you read it that way. I'd put that in the umbrella of SNR, as my intent is to advocate for better signal - both in quantity and quality.
Where I think we may disagree is that existing filtering capabilities are sufficient and broadly used. I mean, if you can imagine a world where it takes users less effort in setting up their twitter account to get the same quality output, then we're in agreement that there's work to be done on signal and noise. Currently it's a hell of a lot of effort, and you still run into a lot of unnecessary strife and bullshit. I'd push you to consider that twitter's current feature set around discourse is also not the end all be all of online communication, and there is room for improvement. If you can accept that there is room for improvement in these domains, then we're on the same page here.
In fact I think this very conversation is a decent example of how the design of a medium can cause some unnecessary strife and result in the rather silly situation of being in violent agreement. Food for thought.