Yes I think that is how it should be. It would be a different world without the gender mixing in schools. I don't believe that having girls and boys in the same classroom causes any distraction that would not be present if there were all boy all girl classrooms. That is what I believe.
Maybe because everyone is talking about equal rights that they forget that sexes are very different and should be not considered in the same class. The female is the weaker sex and even says so in the bible so it is the males job to protect her and be fruitful and fill the earth.