If you want to downvote it, go ahead, use whatever reasoning pleases you. But please be careful about quoting a post calling on others to downvote. Campaigning for upvotes or downvotes is frowned upon, it breaks the entire premise of "The wisdom of the HN crowd."

If you feel this person's anecdote is not helpful, it miht be better to reason against it directly rather than engaging in meta-debate. You risk re-opening a debate about that post rather than the current topoc.