Your analysis of the BP accident is, to some degree, totally correct.
As an engineer I have run into the same situation, to a much lesser degree, many times. We advise the client of the pitfalls of the bean counters and short-sighted management and we are overridden. Several years in the future when the fecal matter hits the rotary impeller all of the parties are long gone and the new people in charge just pass it off as bad engineering.
The real enforcers of codes and good engineering are the attorneys. When one of these situation results in major property losses or death it is time for someone to pay out the big bucks. That is when some one digs through all of the documents and finds the memos and minutes of meeting when the engineers recommendations were ignored by the management team and the bean counters.
We may have lost the perspective that codes are a minimum standard and the design team is responsible for evaluation of the design and to, when needed, provide a design above code minimum based upon good engineering judgment (we almost always loose this argument). So bring on the attorneys, the forensic engineers and the checkbooks.
Jerome Valenti, PE