Why does consciousness matter?
It matters because we are definitely conscious organisms that can feel, see, experience, enjoy, suffer, initiate, and so on. We are conscious of some of our internal events, and being conscious of them is "a primary phenomenological aspect of our human existence" as Benjamin Libet an American neuroscientist averred. In that regard, every one of us has his or her own first-person data about what they experience. As Bertrand Russell argued, this is a kind of data that we are the most confident of. Therefore if understanding human nature at the deepest level is the most important pre-requisite to forming the fabrics of any social contract, it is imperative to have an accurate comprehension of it.
Consciousness matters because we are conscious observers and thinkers who are capable of observing external events and concluding their meanings, their recurrences, or their causal stories. Being conscious of those renders us capable of judging or decreeing, rewarding or punishing, praising or defaming, or rescuing or killing. Therefore our consciousness is a solid ground to conclude that we have ethical, moral, and legal responsibility. In this regard, studying consciousness appears not only to be necessary, but to have also social and survival value.
Consciousness also matters because some of our conscious states are identical to the brain's activities. There are a number of neural, chemical, and cellular activities in the brain that suggest some forms of association between those events and consciousness. By studying some neurological cases, by observing the brain's activity by MRI and fMRI, and by experimenting with drugs to alter behavior, scientists have accumulated a great number of third-person data about consciousness that are begging for scientific explanations. Having known that, a natural question arises: What do those activities buy us? If science is to explain things in the world, finding an answer to this question is one of the most urgent and important tasks of modern science because of its clinical and moral implications.
Also, there are many theological questions that can be answered by better understanding the phenomena of consciousness.