Easy, because the commenter making that argument is a proponent of men getting vasectomies, and they are choosing to interpret the statistics in a way that is favorable to their position. Just like what the people you are describing were doing with covid stats. Just like what people do with statistics on gun crimes or school shootings.
To me it seems like whenever statistics get posted on HN the discussion is bound to devolve into pointless arguments. Statistics are crucial and necessary and we have to have hard data to support everything when said hard data supports MY positions, but when it supports YOURS it's obviously biased and incomplete and inaccurate and useless.
And I guess I should point out that I am in no way saying statistics shouldn't be used when making decisions. It's just that whenever I see them posted here, it means I'm not going to learn anything from that particular comment thread and it's time to move on to the next one.