As the one who wrote that, I'm obviously in favor of asking for explanations, but drethelin's point (that the first few upvotes or downvotes are not always the start of a cascade) is important to bear in mind before concluding that LW feels really strongly in general.

In addition to random noise, there's the phenomenon that immediate votes are usually from the very active users who are reading Recent Comments, and that those users are often more critical in their voting behavior than the people who only check in sporadically.