Plain simple text sites (Hacker News is a good example) have one great feature: they're inherently far more accessible to those with disabilities, particularly

Plain simple text sites (Hacker News is a good example) have one great feature: they're inherently far more accessible to those with disabilities, particularly those who rely on screenreaders or text magnification or similar. Of course, following proper web standards could make the flashiest of sites accessible. But simple paragraphs of text, links, and lists, survive automatic mangling most of the time, whatever the target format is. You'd be reaching a significant population there that's often excluded. (It may be of regulatory compliance relevance, too.)