Wait, how does interacting with a troll damage the signal to noise ratio? Whose signal? Whose noise?

EDIT: It has been pointed out to me that the relevant signal-to-noise ratio is in the Recent Comments feed, which makes plenty of sense. I have been convinced, and will not interact with people I perceive as trolls. Note that at no point did I reply to anything Shoga said, nor do I defend Shoga's views, nor do I welcome Shoga's participation on Less Wrong. I was simply trying to understand Joshua Z's comment.