Does the Semantic Web try to impose meaning from the top?
No. What the Semantic Web technologies do is to define the “language” with well understood rules and internal semantics, ie, RDF Schemas, various dialects of OWL, or SKOS. Which of those formalisms are used (if any) and what is “expressed” in those language is entirely up to the applications. Ontologies may be developed by small communities, from “below”, so to say, and shared with other communities.
