The process of language evolution is self-perpetuating. What we mean is, as a species, we do not intend to pass on language; we just do. The most important consequence of attenuation in vocables is the promotion of linguistic behavior. Somehow, as we inherit it from previous generations of users, some of the history is lost and forgotten and somehow the residuals give rise to more linguistic behavior. In the loose terms of the first law of thermodynamics; nothing is lost and nothing is created. Thus we can say that we reuse all that we already have in our linguistic interactions and as it becomes more and more attenuated we have more building blocks to generate more linguistic behavior. Moreover, as a language becomes older, its constituents are further along in the attenuated process so linguistic combinations are significantly increased as to involve complex sentences. But most of language is used in reference to something else, that is, without being conventional, linguistic behavior can coordinate and generate actions much beyond simple deixis can do. The fact is, linguistic behavior is an emergent feature of the attenuation process, much like flocking behavior is an emergent feature of a group of birds flying. But linguistic behavior is more like flocking behavior in which, somehow, the birds have been forgotten. If we were to copy successively a video of flocking birds, each generation would lose some information possibly leaving a blur in the place of birds, nonetheless, the blur could still trace the patterns that are emergent.
Similarly, with attenuation, we have the behavior but we have forgotten what gave rise to it. However, attenuation differs from our example because the resulting linguistic behavior furthers the process of attenuation which in turn gives rise to more complex linguistic behavior.