[grawprog]

When you're reading a several hundred page technical report, those double spaced periods are really helpful for picking sentences out at a glance. You don't tend to read those in order from start to finish. There's a lot of jumping around, highlighting things, writing notes. Having sentences be easily visually distinguishable at a glance when scanning a page is fairly helpful.

It's kind of like trying to read tons of code with or without syntax highlighting.