A common bandwagon in post 9/11
Firstly, if you even begin to mention the No Child Left Behind Act, you better be prepared to read and realize that most of the legislation is very agreeable, including ideas about teacher training and funding as well as emphasis on how to close achievement gaps. You can read the whole thing here, but this article is about a specific piece of the current system under the law which is about accountability and standardized testing.
Imagine, you are trying to hold your doctor accountable for your health. What would you do if he/she kept no records, had nothing on file, and basically used their memory to make decisions about what to do with you based on what their "gut" says?
That would be a dangerous doctor to use. Similarly, states and our government use standardized testing data to make all sorts of decisions about funding and curriculum goals/progress. Without the tests, the data stops, and so does our informed decisions.
In saying that though, the way in which this data is gathered in addition to the pressures facing schools today makes for a combustible situation where many people begin thinking the tests are the enemy when in reality they are our ally.
Examples you ask?
Teachers have a limited number of days to teach an awkwardly huge curriculum, so when days are used for testing, it seems bad. Is the problem the tests or the lack of school time?
A student has a bad day and the test doesn't reflect their true ability? Large sample sizes help take care of that statistically.
Teacher incentives to teach to a test and not for learning? Is that the fault of the district leadership putting pressure on their teachers for "good" test results, or the test itself?
Standardized tests give leaders the data they need to make decisions. The implementation of those tests need to be kept separate when talking about whether or not tests are bad because tests give us amazingly useful data. Furthermore, implementations of tests are hounding us due to school structure, not the tests themselves.
You could fix the structure of the schools, you could change the way the tests are given, but you need data showing what students know on a standardized scale so that real statistics can be done.
If you want something to complain about, complain about how the structure of our education system hasn't adapted to our data dependent financial connectivity which relies on data in order to function properly. If we lose the data, we lose our efficiency, and if we lose our efficiency, we lose.