Companies that create textbooks are also the same ones who provide the standardized tests that are mandatory due to laws like No Child Left Behind. Instead of creating curriculum designed to educate children in the best manner to be ready for the future, these companies rely on schools to turn to their teaching method to prepare their students for the test that they have created.
There are many other problems in the education system, but this is a problem that can be solved at the national level. Having such legislation will help schools find the best ways in which to teach children without being influenced by the sales of education/testing suites.