The problem with testability is that even the most reasonable of success criteria can be non-testable—and if a success criterion is not considered testable, it isn’t included in WCAG 2.0. Whether the criterion is an otherwise useful technique that improves accessibility is now irrelevant to whether it gets included in WCAG 2.0. Due to the testability requirement, many useful success criteria have been removed from WCAG 2.0, and others watered down.