Because people are emotional and don't respond to statistics like that. 2 planes crashed over a single, critical software usability defect. Now Boeing is a complete trash company and is doing many things wrong. Airbus is perfect and does nothing wrong. With such a small sample size, it could very well be that Airbus is much worse than Boeing. But that's just not how people will perceive it. These businesses know that and know they need absolute perfection.