The parallels between song bird learning and human language learning are significant even on a non-molecular level, so studying the genetic components involved is certainly a worthwhile pursuit. The parrot genome also shows a lot of promise, considering that they can produce more similar speech to our own and demonstrate similar levels and types of cognition to ourselves than even many of our most closely related species, such as the other great apes. The allelic components that govern these phenomenon are certainly worth studying as they have the potential to unlock secrets not just about the birds themselves, but about ourselves. The idea that we may be able to apply what we learn to human medical science is certainly a reasonable expectation and at the very least, even if we don't learn enough to combat speech disorders directly, these studies will provide a foundation on which to base other studies that may yield more relevant data, as well as contributing to our vast database of knowledge that at some point may even be applied to something that we haven't forseen yet. "Scientists" as a whole do not make a lot of money. You would be lead to believe that they do, due to the large amount of funding that many projects receive, but this money is not going into the pockets of the scientists; it is consumed by the costs of the experiments and equipment and a lot of it is syphoned off by the university or organization at which the scientists are employed. The only means by which a scientist can reasonably expect to become wealthy through these studies is by publishing enough research and becoming valuable enough to their field of study that they can make a living on the lecture circuit and by convincing their universities to consider them for raises and tenure. However, these scientists are generally not paid to publish their work and are usually not compensated for their involvement in the studies. In fact, they are often required even to pay their own travel expenses. Humans are not "defying" natural selection, they're reacting to selection pressures in a different way than other organisms. This is the exact evolutionary phenomenon that has always motivated speciation.