I agree that data scientist does smell a lot like recruiter/marketing speak. But on the other hand, just because it's a new title doesn't mean it isn't valid. Reducing everyone down to "Scientist" is no more helpful than saying a physicist isn't really a separate job, but just a specialised branch of mathematics. Or for that matter, CS is just a narrow branch of mathematics.
Eventually you have to distinguish new fields from the old, even if they have a lot of commonalities.
Well, yeah...when there's specialized knowledge required for the job (like, say, "physics"), it's obviously a good idea to change the job title.
The problem here is that "data scientist" adds no semantic value above and beyond "scientist". A scientist of data, you say? However will we find such exotic creatures!?
Eventually you have to distinguish new fields from the old, even if they have a lot of commonalities.