W3C doesn't create standards, they document status-quo as a recommendation for standardization. Most major browser vendors have a chair on the W3C, and they hash out differences there, however many browsers have not fully implemented what people want in HTML5 or even HTML4 for that matter fully. The lesser used features are not implemented consistently, so the W3C cannot really document them accurately without much discussion. Basically the typical model for standard creation does not exists here. There is no reference implementation like there is in all of the examples you mention.