I don't perceive any blame in the comment you are responding to, only observations relating to the history of bridges and the responsibility that comes with it. What did you feel was assigning blame when you read it?
Whether or not it was intended, the entire comment implies exactly that - particularly with the call to the responsibility, ethics and standards of the civil engineers.
For example, if someone dies in a car crash, it's a little out of context for you to focus on the responsibility and ethics of the car designer over and above the circumstances of the crash. Usually the latter focus is for when there's concern about said ethics and responsibilities.
