> Textualism is pure nonsense, used to present a false sense of rationality

No. You're just saying that people have biases and thus everything is a lie.

Textualism is a thing, and exists outside of law. Textualists think that the authors specific words are important. "Why did Tolkien say X? It must matter, he's a careful author."

I value it in the field of law because legal disputes caused by textual confusion can be avoided through careful writing and textualism leads to the type of thinking that is capable of that. And if nobody cared about the words, how sloppy would the thinking also be?