Why don't liberals more aggressively promote the Ninth Amendment?

[I spent the winter writing songs about getting better]

Antonio, you just have to understand that you and 18th century Americans have very different legal conceptions of rights. They disagree with your entire foundation for this conversation, and vice versa.

Pretty much this. Trying to analyze it from a modern day context is pointless. Of course this also highlights the absurdity of the "OMG THIS ISN'T WHAT THE FOUNDERS WOULD'VE WANTED!" type of arguments.