Good question! It's a pretty subtle difference, but the short answer is that although its simple nature is nice, there's been too much in the way of core functionality that's been left out. Everything can be patched with additional gems, but you're then moving away from the original goal of minimalism. [I wrote some slightly more extended thoughts about this here](https://github.com/12-oz/pliny/pull/65#issuecomment-41350760).