To get back on topic, I guess the point is part 121 flying has a very good safety record. A few factors that contribute to this include the general professionalism of the individuals flying (doing it for a living regardless of whether you think the person has tact), the regulations (many written in blood), training, technology (TCAS, GPWS etc), CRM, ATC.... the list goes on and on.
All that aside the business is risk mitigation management. With all the focus on safety, the risk is very low but it's still there.
What is concerning about this accident though is the rumors surrounding hiring practices/training, people with questionable training records being put into planes increasing that risk. From what I've heard the FO involved in the accident failed upgrade at his regional, the regional pushed back on the LCA and she told them they could have her check airman letter instead. Eventually they accepted her decision. Then the guy went to Atlas, had difficulties in training, was sent home but eventually brought back.