> I think it's mostly propaganda by Knuth and Kernighan (TeX and troff) that makes people want this.
> Let's keep HTML simple!
was unexpected. Knuth as propaganda!
The discussion noted some O’Reilly books sentence-spaced, and layout software had different levels of support with TeX notably supporting it. And that’s the key: it’s a typographical layout choice. For document input, for writers, it’s a matter of markup for the output typographical layout not double-spacing per se. It’s an aesthetic choice only, similar to the spacing we add between letters, around punctuation etc.
So the question is not, should we support double spacing, but: should we support this sentence spacing typographical technique?
Because double spaces are an hack used to achieve layout they should not be necessary, but word processors not supporting it leads to people implementing it themselves. (If you’re a product manager, this is the sort of thing you spot to indicate a missing feature.)
It gets worse on the web: because most white space is collapsed together the double-space trick doesn’t work, and it’s _very_ hard to do in CSS.
Marc Andreessen’s 1993 comment ‘how is a text widget supposed to know where a sentence ends and where it doesn't? That sort of syntactic analysis we can't do...’: yes, it’s hard. English parsing is hard. Other languages are hard. I don’t believe that’s a reason not to do it any more.
My website has sentence spacing [1] in CSS as a purely aesthetic choice based on a technique by Tom Fine [2, 3]. And it’s automated: I run the site text, single-spaced, through a Python script that understands sentences and marks up sentence spacing.
[1] https://daveon.design/about-dave-on-design.html#typography-&...
[2] https://hea-www.harvard.edu/~fine/Tech/html-sentences.html