Placing software into production will uncover quality-related problems at a time when it's expensive to correct them. If the neglected quality attribute requirements have highly visible results, they empower political opportunists with 20/20 hindsight to suddenly become interested in the project like never before, and the neglected quality attribute requirements become the subject of a witch hunt.
Whoever is funding a project owns the responsibility for conveying the requirements, including quality attribute requirements. And, in many cases, the project sponsor neglects conveying requirements in general and quality attribute requirements in particular. In essence, the project sponsor refuses to assume the responsibility, thus in effect conveying "Build me something. But I don't want to tell you what I need."