You misunderstand, Pete P. As an individual, I have little chance of being killed by a fatal manufacturing or engineering error in an airplane. For the flying public as a whole, however, there is a high likelihood that someone will be killed by that error - and given the nature of commercial air travel, many people at the same time (e.g., Indonesia and Ethiopia).
If you’re willing to stand up and say that a certain level of fatal errors in transport aircraft design and construction are acceptable, then that’s your right - and I hope that my life never has to depend on your efforts. For myself, I think the right number is zero, especially when those errors can be avoided by management not putting their hands over their eyes and ears and wishing the problems away.
We don’t know yet who failed on making sure the door plug bolts were installed, but we need to know so that it doesn’t happen again. Congress, having oversight of the FAA, is doing exactly what it should do to investigate the failure and see what can be done to prevent future occurrences.