What are the most underrated skills or areas of knowledge that aspiring data scientists often overlook, but are crucial for success in the field?

I’d say a solid understanding of business strategies and tactics and the dynamics of the industry in which a business operates. This knowledge allows a data scientist (or analyst) to understand what the results/conclusions mean and how they can derive insights from the data analysis to benefit the business.

I talked to managers and directors from a number of large companies. They told me that they could hire mathematicians or computer science graduates to do data analysis, but these folks could not help them in using the findings. They did not have enough business knowledge until they had been around for a while. They were delighted by the program my colleagues and I put together that included enough math, programming, and database expertise within a business degree to allow the graduates of this program to function as data analysts who could make the results useful to the business.