Great write up. Thanks for taking the time. Your Organizational Culture comment really caught my eye, such as:
This was so contrary to the corporate culture and belief system that my analysis went straight into the round file.
There is technical success for a project, which most IT staff tend to focus on, and then there is business success of the project. I am sure your projects were technical successes, but I've found that the business has to want to know the truth. I've found that BI must be sponsored by the business side, and not the technical side.
Going into a project, if you suspect that the project is not sponsored by the business side, keep it technically sound, but don't be surprised when the truth is ignored. Most organizations need a high level of pain before they will be ready for a change.
The more you are prepared, the less you need it.