We do not take the structuralist position that each language represents a tidy system in which units are defined by the oppositions they enter into and the object of study is the internal system the units are supposed to create.
(Bybee & Perkins & Pagliuca 1994)
A legacy of the structural tradition in linguistics is the widespread acceptance of the premise that language structure is independent of language use. This premise is codified in a variety of theoretical distinctions, such as langue and parole (Saussure 1916) and competence and performance (Chomsky 1965). A further premise of this legacy is that the study of structure is a higher calling than the study of usage and is a potentially more promising avenue for uncovering the basic cognitive mechanism that make human language possible.
(Bybee & Hopper 2001)