Interesting read. I think a lot of it is spot on, but there are a couple of points that are not quite solid.
1.) Suicide. The early half of the 20th century in England was pretty terrible. Lots of poverty, two world wars, and a depression. Around the middle of the 20th century there was something much more likely to have brought about a decline in suicide. Money. Between the general increase in the quality of life and peace, it stands to reason that less people would look to check out early.
I think there is something to be said about the "split second decision" but I don't think it is as overwhelming as is portrayed in the article.
2.) Fantasy. I'm sure there are people who own guns for the fantasy that they'll have to use them, but there are also plenty of people who own them just to be prepared and would rather live their whole lives without using them to take a life.