Oh, grammar bugs me sometimes too, but this is not even grammar. This is an issue of typography. It's not even an accidental error that the writer is arguing, but a systematized conceptual error rooted in what is by and large, a quirk of outmoded technology.

From my perspective, dude is making a mountain out of a molehill because people haven't changed as quickly as he thinks they should because books exist that inform people of the current convention, a convention which no on else seems to place any sort of emphasis on.

I'm not at all an advocate for bullying of any stripe, and certainly not of child abuse, but I firmly believe that some people should have gotten their asses kicked more (or even just once, perhaps badly) as children.

Now, had the article been framed more along the lines of, "hey, I'm a huge typography nerd and as such, I wonder if my readers were aware of the convention around spaces after periods or full stops? Here's an interesting story of how the convention was arrived at, blah blah blah, here are some other interesting facts about typography, etc." then, cool.

Maybe I'm just getting tired of the near-mandatory superiority and snark of internet articles, but a high and mighty article about typography is apparently where I draw the line. To the writer, I say, "No, nerd of the obscure. Lick my nuts and do it well since you're so concerned with details, period, space, space.