The concept of common standards and regular assessment should not be questioned. Blocking information because you fear how it might be used in the future does not help anyone. As the US moves toward uniform standards there will be a learning curve and some mistakes made. But the only way to get better is information and transparency.
Parents who “opt out” have done education reform a disservice. Like it or not, testing is the best way to produce uniform standards and accountability. Opting out is more common among higher income families. If the kids from rich families don’t take the test how can we know what poorer children are or aren’t getting from their schools?