@plainoldme,
To an extent there's truth to the statement that students are taught to the test. This has been the case since the first school and classroom opened. After all the idea is to teach the student and teach them well enough that they will pass the exam.
Further, there are plenty of students who know something, plenty who know quite a bit. It will vary from student to student and hi get upon variables such as the educator, the overall intelligence and diligence of the student, as well as the student's interest in the topics discussed.
To say these people know nothing is wrong. To take it further it can be perceived as a lie.
Regarding the topics/subjects which you believe a ninth grader should know, clearly this will be different from one student to another. Again, it will hinge (in part), on the teacher, the student level of intelligence and diligence (as well as a number of other variables).
As to your attack of the parents being at fault for not having taught these things to their children, I wonder what the purpose would be of anybody attending school if they already knew these things. Correct me if I am wrong (I'm not); but, isn't it the responsibility and the goal of the educator to bring these morsels of knowledge to the students?
Lastly, no, not all parents or guardians possess knowledge on these items. Some were not born in the country where their child is attending school, for some, English is not their first language and in some cases, the parent or guardian is still learning the language along with providing a home, food, caring, clothing and other things, it is not unreasonable to expect their child to be given these lessons from the teacher.