Critiques are valuable arguments for several reasons. Critiques are highly generic, that is, they can be applied to a large variety of cases. The resolution always makes critical assumptions, such as who should act, how the policy should be implemented, why a particular area is important, etc. The critique provides a general argument that can be used to attack those critical assumptions. Critiques have multiple consequences, that is, they can minimize the affirmative advantage while also providing an argument to weigh against whatever advantage the affirmative can claim.
Critiques integrate many arguments into one position.
Because the case arguments frequently stem from the critique, the negative has a position in the debate that is coherent. Critiques frequently have a priori implications. An a priori argument is one that must be resolved first, usually before the substantive issues of the debate are resolved. In our example of testing, the negative could argue that policies that reinforce racism or sexism are so evil that they need to be avoided absolutely. If testing is racist or sexist, it should be rejected regardless of substantive benefits that might result from increased testing.