The problem is that industry has coopted the term data analyst to mean something more like data reporter or data descriptor. There often isn't a difference between business intelligence and data analyst. Many data analysts are using tools like Excel, and don't have good programming skills. A data scientist will generally be involved with prediction, and use more sophisticated tools than Excel. This isn't to knock on data analysts (or Excel), they do good and useful work. The proof is in the numbers - a data scientist makes a significantly higher salary than a data analyst. Similarly quantitative analyst got taken over by finance. The term statistician is actually pretty accurate (data science is basically applied statistics), but usually people don't call themselves statisticians unless they have a degree in statistics. With that said, the term data scientist is not at all well-defined, and the field is quite diverse.