Particularly Foone has ADHD, if I'm not mistaking the specifics. And posted about it being the reason for the choice of the choppy-form (just so it's clear I'm not spilling beans).
But frankly, Twitter is sorta alright because authors' efforts still tend to be less long-winded when paragraphs of two hundred words don't quite work. I'm really tired of verbose yada-yada from HN, so finding myself actually attracted to links to Twitter—even though it's a hot mess in most other aspects.