Doesn't make sense. If the content is 'bad', moderator could expunge it. Or writer could be counseled on giving better posts. Or any number of things.
The voting system on HN sometimes demotes bad content. Far more often (discussed widely elsewhere) its used to assert agreement or disagreement. When used in this sense, its a sort of instant-poll.
In the case of anecdotal argument, it forms an ad-hoc 'scientific' experiment. The HN population weighs in using their own experience. Those who's memory (or ok, memory-triggered emotion response) aligns with the author may upvote etc.
To 'bad content' is uniformely suppressed instead, this social experiment is lost, and the community loses. The merit of instant-polls is debatable, but other such polls are supported here. In fact the test group on HN may exceed the original 'scientific paper' group by an order of magnitude. Its statistical significance may exceed a graduate student's narrow study.
