I've been working with big data since before it was a term and currently run a scientific software company that touches on many aspects of "data science". Many of my colleagues also work in the field. I've seen many fads come and go. Data Science as a profession is one of those.
Most people who call themselves data scientists are really just doing "big data" processing using tools such as Hadoop. They are delivering results to managers who have jumped on the big data band wagon and, not knowing any better, have asked for these skills. In 99% of the cases, the processing is simply haphazardly looking for patterns or running basic statistics on data that really isn't that big. However, there is a lot of low hanging fruit in data that hasn't been analyzed before and most practitioners who've suddenly become data analysis experts are rewarded for trivial findings. A tiny bit of statistics, programming, and data presentation skills go a long way.
Compare this to the Web Masters of the late 1990s. The Web was new and managers knew that they needed Web sites. HTML and CGI were techie things but also fairly easy to learn. A group of people quickly figured out that they could be very important to a company by doing very little work and created the position of Web Master. A tiny bit of programming, sys admin, and design skills went a long way.
Web Masters disappeared when IT departments realized that you actually needed real software developers, real designers, and real sys admins to run a corporate Web site. Sure, the bar is still low, but expertise beyond a 'For Dummies' book is still needed. And, few people can be experts in each area, hence the need for teams.
Real data science has actually been around for a long time. Statisticians and data analysts have been performing this role for decades and have built up a lot of rigor around it. It a tough skill set to develop, but a very useful one to have. "Big Data" distracted people a bit and let the current generation of data scientists jump in and pretend everything was new and we could throw out the old methods. As the field evolves, data science will necessarily transition back to the experts (statisticians) and become a team effort that includes people skilled in programming, IT, and the target domain (analysts).
That said, there's good money to be made right now, so if you have Web Master on your resume, you might as well be a data scientist while you can.