That's probably because "data scientist" isn't a job description, it's a trendy title for a whole constellation of jobs that involve looking at data. I would expect that the Wharton grads are probably doing work that is fundamentally different from most people with hardcore academic stats backgrounds.
I think this sentiment is roughly correct. It's basically the same for programmer as there are many jobs that involve programming. Note that data science doesn't necessarily mean machine learning, and there are lots of data scientists who do powerful work with stats that doesn't involve anything that looks like ml.
The jobs for people working in machine learning tend to fall into: software engineer (machine learning), research engineer, and research scientist.
Yann LeCun has an excellent Quora Q&A where he delves into the differences of the roles. I do not have the link on hand but it is probably easy to find.
