I have had more teachers actively advocating voting for right wing parties than left wing parties. And once had someone in biology class tell me that he thinks that evolution and creation by god are equal and we should try to merge those theories. And I live in a very secular part of Europe.

But hey, both you and I are telling anecdotes. The only conclusion for me is that public school exposes you to people that do not think like you or your parents. Something, we are less and less exposed to. If that is good, anyone has to answer for themselves.