Quindlen was criticizing the application of standardized testing (perhaps in the wake of the controversial "No Child Left Behind" act which some say placed too much emphasis on standardized testing). Quindlen's argument is that if standardized testing is to be used, it should at least be interesting and more importantly, such testing should not edit works of literature to the point at which significant meaning is lost. Actually, she is arguing that literature should not be edited at all.
Quindlen doesn't think children are too feeble and weak to read controversial issues because they are exposed to such issues through the media and Internet every day. In fact, by sanitizing (editing out anything remotely controversial) literature, the test will not challenge the student.
Those who design the test claim that anything controversial might distract the student and affect his/her performance. Quindlen's response is that the kids can handle it and more to the point, if all remotely controversial issues are edited out, what is left can hardly been interesting or engaging. Also, to edit in this way is historically irresponsible. Quindlen notes that in Isaac Singer's excerpt about being a young Jew in prewar (World War II) Poland, all references to Jews and Poles were taken out.
Quindlen notes that there are other consequences of this editing. One is that the students will determine from this that those designing the test have no faith in their (the students') ability to handle differing perspectives and challenging intellectual material. Quindlen argues that this is sending the message to children that "we don't think you're smart enough."
But what do the kids learn from this? That the written word doesn't really matter much, that it can be weakened at will. That no one trusts a student to understand that variations in opinion and background are both objectively interesting and intellectually challenging.
This also tells the student that there is no power to the written word (as literature, laws, etc.) if we can simply edit things that don't appeal to a particular way of thinking. So, clearly Quindlen is against this manipulation of literature, in these tests and in general, for a number of reasons, all logical. This kind of editing also sets a dangerous precedent where those in power of educating children have the ability to subject students to a particular worldview that they only assume is the best for everyone. This is quite audacious and ignores one of the hallmarks of American culture: diversity.