Thanks for sharing that video, Donald.
In context, I don't think it's fair to characterize the speaker's perspective as dangerous, or of categorically favoring current users over potential new users. Obviously there are a lot of tradeoffs around backward compatibility, and no one-sized-fits-all solutions.
One of the most powerful points Brian made is that the large user base of Java (or Python, etc) is an immensely powerful source of leverage. Each incremental improvement to the language, standard library, or associated tools will almost immediately impact a lot of users and improve their lives. It's kind of an obvious point, but I think he expressed it very well.
On that note, I lurk on this list regularly, but generally don't really contribute. I do see the awesome work that ya'll are putting in on a day to day basis, and I see the results in the wild. Thanks to all of your hard work, the packaging situation has vastly improved, and continues to do so, especially with pip and wheels. All your hard work has definitely made my life better, for one.