The microformats site states that microformats are:
Designed for humans first and machines second, microformats are a set of simple, open data formats built upon existing and widely adopted standards.
I think the emphasis is wrong and that what should be aimed for are files that are primarily machine readable, but human editable. There are already plenty of places where information is provided in human formats – what’s missing is a format for machines to use. Anyone who has ever looked at an RDF file will realise that such files certainly aren’t meant for human readability, but they certainly do meet the human editability criteria I think is far more important.