I agree with this. One thing to consider however that a fundamental concept of the Six Sigma approach is to bring processes into control. In my experience there are only a limited number of cases where this works in a complex environment with many factors that influence success. For instance using process control charts on transactions per day is a valid approach for a large retailer but will generate a largely random output when trying to track performance of sales by specific product groups.
It would be well worth any analytics professional to become familiar with the basic toolset for Six Sigma.