@ Scope creep...
Possibly. But I agree with the sentiment of the article in that it's not necessarily scope creep that causes projects or programmes to fail, but the lack of an adequately scaled or robust programme framework with the rigorous functional governance in place to manage and control it.
"The most insidious way this happens is when the client's idea of what they've asked for gradually changes without them realising it. Because we're all supposed to be agile now the requirements can be as vague as they like"
But this isn't "Agile". It sounds as though your organisation (like many) don't understand the method. You reap what you sow though right...