Some of us who care about typography like to double-space our sentences. By that, I mean leaving two spaces (or similar gap) between sentences. For me, it makes blocks of text slightly easier to read. (No, that’s not just a thing for old-fashioned typewriters — arguably, it makes more sense with proportionally-spaced fonts, which have a proportionally narrower space.)
HTML doesn’t make that easy, of course; but on most sites, it’s possible by making one a non-breaking space (U+00A0, which can be typed with e.g. Alt+Space on a Mac). That used to work here, too, I think; but no longer. Then, by using an en space (U+2002). But recently that has also stopped working: the site seems to convert all groups of spaces of any kind into a single basic U+0020 space. (I’m posting this with figure spaces — but without much hope…)
Why does the site go to all this trouble to avoid groups of spaces and/or other space characters? Are they so harmful? Is typography so offensive??