It's likely a mixture of all these factors, the brain drain could absolutely be responsible. At least it would not be the first time in history that a company

It's likely a mixture of all these factors, the brain drain could absolutely be responsible. At least it would not be the first time in history that a company has lost the engineering spirit. And instead the business people have taken over, so that details like disaster plans become less of a priority. A business person and an engineer will always view risk differently, better disaster plans is a kind of insurance that is a lot harder to sell when too many business people run the company.