As stated in
The False Choice of Schema.org The Beautiful, Tormented Machine.
Basically, becasuse they aren’t reusing the good work done by the Microformats community or the many Web vocabulary authors that have already put multiple years into creating solid Web vocabularies through a public review process.
So, as a front-end developer who has embraced semantic markup long ago:
- I want RDFa supported for schema.org as a first class language.
- I want Microformats continued to be supported.