It is pretty hard for one parent to change things for the better, even if just for their child in one classroom. The administration and teachers have so many other things to deal with. It's much harder to change the entire school culture. You can volunteer, and you should!, but you still won't make as large an impact on your child's education as you would hope. In some ways, this is good, because there are lots of crazy parents out there who you don't want making impacts on your child's education, but it's also bad if you're not that crazy parent.