The tech thing that annoys me most frequently is when people insist JSON is better than XML. So much breath, so much time, is wasted by those setting technology standards on this non-issue!
XML is no harder to parse than JSON, whether you're writing your own parser or reusing something from your language's standard library. Especially when you add the schema validation & namespacing that standards organizations rely on.
@technomancy, @alcinnz, I've just discovered the existence of EDN as a mark-up language, which basically gets to the level of TOML but looks better for nested data. Of course it's nowhere near as popular as the other two (or three, I barely see anyone choosing s-expr for new projects anymore), but for human it feels like a breath of fresh air.