There's a well known principle that extraordinary claims require extraordinary evidence. It doesn't necessarily follow that non-extraordinary claims do not require extraordinary evidence (or elaboration etc.) but it's a good starting point. Venue also matters. Applying the standards of a courtroom or thesis defense to a non-controversial claim in a casual forum is not a good-faith behavior. It's an exhaustion tactic, unfairly placing the entire burden of proof on the original speaker as though the sea lion's preferred contrary position should be assumed as a default. That's why it is so reviled among people who actually value a spirited exchange of ideas.