[Edit: Sorry, I replied to the wrong post. It was btilly who wrote the following quote, in another reply to the parent post.]
I prefer the way it looks.
And in the end, this is why so many petty typographic debates are futile.
Some aspects of typography are about practical matters. The choices here tend to be quite objective, and almost everyone will agree about which choices are better, at least once they appreciate the significance of the difference. Using a programming font where some characters look too similar leads to bugs. Setting a magazine article with a huge line length and tiny font size will likely reduce reading speed and retention.
Other aspects of typography are about subjective taste, a matter of art and personal design choices. This is almost always the case with trivial whitespace and punctuation issues. Does anyone really fail to understand the meaning of a post here on HN because the poster used a double-hyphen (--) as informal punctuation instead of looking up the code for a typographer’s em-dash (—)? Will anyone die if I personally set my em-dashes with a space either side in HTML because I think the “standard” tight setting looks awkward? Of course not.
Sometimes a change falls between these two clear categories, and this is the case with doubling spaces after punctuation. To some extent, the basic appearance is subjective, but if the design choices result in rivers appearing in the text, this will almost certainly impair readability, an objectively worse situation. However, in these cases there is rarely a better answer than having someone who knows what they’re doing examine the specific piece of typesetting and make manual adjustments to fix the problems. It’s an exercise that I think anyone seriously interested in typography should try at least once, both to understand how easily any automated system can get things wrong in specific cases and to understand how impractically time-consuming and expensive it would be to have human operators review everything and fix all such minor details manually.