By that logic, "fake news" is now unusable because Trump weaponized it, despite the term accurately describing a real phenomenon that existed before and after his usage. "Gaslighting" would be suspect because it got picked up by people dramatizing ordinary disagreements. Every useful term for describing social dynamics gets captured by someone with an agenda eventually.
Hitler liked chocolate, doesn't mean you shouldn't eat chocolate. "You used a word that bad people also use" is not interesting - it's a way of avoiding the object-level debate while still claiming moral high ground.