What a great point. I've been struggling with the epistemological implications of the copula for the last few months. The existence of the copula and its use seems to imply a shared objective reality, when it's perhaps more explainatory to label the copula as a reality constructing mechanism.

Either way it's use as a universal quantifier eschews nuance. Patterns like "A is B" necessarily lead to differences in reality that are easily resolved when phrased like "I percieve that A is B". Copula-induced fights are ubiquitous.