Your PS statement reads like an endorsement of the tactics you oppose, "But online, the loudest people seem to be the most passionate -- and often persuasive." You seem to say confrontational approaches (this video is clearly very confrontational) are the most effective, despite saying elsewhere that you oppose confrontational approaches.
This is a very good question. What approach is best depends on the audience and the goal.
When it comes to the general public -- the people we need to reach with the animals' plight -- I absolutely believe in only constructive, positive outreach. No one has ever been shouted into changing their diet. Any rudeness or abuse becomes the issue, distracting from the important message of how animals are abused, and what positive steps everyone can take to help.
However, when it comes to communications within the activist community, we have to keep in mind the audience, and where the mindset often is. Many activists -- especially those who have only recently learned how animals are treated in hidden factory farms and industrial slaughterhouses -- are burning with anger. (I know this was the case for me.) As such, these activists react more positively to those who express the same anger and the same passion they feel. The constructive activists can come across as dispassionate, even uncaring.
This is what I like about Phil and Matt's video -- they show passion. They clearly understand the outrage we feel. They also show how the angry activists can appear -- when you're on the other side, it is hard to realize how you come off to the general public.
Of course, I believe in thoughtful, dispassionate analysis dedicated to using psychology and research to open the hearts and minds of as many new people as possible; indeed, I believe that is my niche. But having dealt with thousands of activists over the past quarter century, I appreciate the need for a different approach in some circumstances.
PS, Feb. 18: Anne and I were trying to figure out something about YouTube, and ended up watching the first 30 seconds of the above-mentioned video. We both burst out laughing ... again. Bringing such joy to our lives has to count for something, no? :-)