I don't really understand the basis of that charge. To me, pharisaism is an inability to see the meaning of God's word because you're too hung up on the form. I really don't see that here.
However, this does seem to be taking things too far. How are we to be an influence on the world, if we totally withdraw from it?
Don't get me wrong, I spent 7 years in a Christian school and it was a wonderful experience overall. However the idea that withdrawal from public schools is the right decision for all Christians in all places seems absurd. I've never understood people's inability to take this issue on a case by case basis.
For a look at how truly hurtful these tendencies sometimes become, check out this June 19th, 2002 post by David Heddle. (If the link doesn't take you straight to the post, just scroll down.)