Triple Constraint

In many discussions about projects, people express the view that Time and Cost are the main controls. In fact, a common view is that projects fail when they deliver late or run over Budget.
But many projects fail because of a focus on time and cost.

The Magic Triangle, or Triple Constraint, is widely seen as the fundament of project management. Controlling time, money and quality is a basic rule for project-governance. There are several variations, e.g. the Devil’s Quadrant.

This concept is generally accepted without much thought or discussion. But should it be? Is (a variant of) the Magic Triangle always useful?