> if it tries to have a unified ontology that's why it's destined to fail, but if it's designed to working with many small ontologies… that's why it will fail! lol, but you can't have it both ways.

You're only supposed to say "you can have it both ways" about contradictory things. It can both be a hopeless endeavor because it is impossible to agree on ontologies and a useless endeavor if you don't agree on ontologies.