Also, in the softer fields, it's possible to contribute precisely on account of one's ignorance of what went before, too much knowledge of existing theories' assumptions sometimes standing in the way of real progress.

You haven't noted the most horrible thing about this: that the fields are still valuable, even still necessary. Us being no good at them doesn't change this.

c.f. medicine before germ theory and cell theory.

c.f. postmodernism, which is notoriously BS-ridden, but anyone who aspires to write good fiction needs a working knowledge of postmodernist techniques, whether they call them that or not.