You're probably being ironic, but for the sake of the readers, I'll point out that most of us in the United States that are older than around 30 years old and learned to type using a formal system (including typing software) use double-spaces.
That's the way we were trained to type. The only thing this proves is that Satoshi was probably not a very young person. I don't think many people believe this anyway (or maybe he just "faked" the double-spaces?).
The joke was a reference back to Goodman's observartion in the original article: "the punctuation in the proposal is also consistent with how Dorian S. Nakamoto writes, with double spaces after periods and other format quirks."
Your comments about prevalence of this technique stand, of course.
That's the way we were trained to type. The only thing this proves is that Satoshi was probably not a very young person. I don't think many people believe this anyway (or maybe he just "faked" the double-spaces?).