I don't think anyone desires fragmentation. It's just the reality of the space. People were exploring options but didn't have support from the key stakeholders who were the browser makers (IE was at its peak) and Google. Firefox and WHATWG advanced some of the ideas in time.
People always mention RDF when the semantic web comes up. It's really important to understand where W3C was in the early-2000s and that RDF was driven by those with an academic bent. No one working with microformats was interested in anything beyond the RDF basics because they were too impractical for use by web devs. Part of this was complexity (OWL, anyone?), but the main part was browser and tool support.