I can't begin to tell your how much this article is a breath of fresh air.
Do you think discussing religion or politics is a good way to make total strangers hate your guts and threaten violence against you and your family and everybody you brushed up against on the subway for the last six months? That's nothing compared to what will happen if you dare to discuss sentence spacing with typography nerds.
Or even worse, ask one what font should be used. Or even worse, dare to suggest that web pages should respect a user's personal font/size preferences (as configured in his web browser) and not force a style that may not be readable on the user's device. Does anyone really think that a single font will look equally good on a 1200dpi printout, a 300dpi Retina screen, a 72dpi CRT monitor, a Kindle, a mobile phone and a wristwatch? Typography nerds will insist that they know best and that you are an evil human being if you dare suggest that they can't possibly know what's best for every single device that might someday be used to display the text. I've actually been personally attacked and banned from an on-line forum (one having nothing to do with typography) for making this suggestion.
Read the rest of the article for a great history on the subject. And I love the fact that the author has deliberately formatted it using an extra-wide space between all the sentences! As a show of solidarity, I've done the same for this article.