In his article, "Return to Basics: A Call to Revitalize R. Hirsch's Torah im Derech Eretz", Daniel Adler makes many good points, including an excellent explanation as to why the teaching of secular studies would be best approached with a Hirschian derech. "In order to prevent confusion and conflict in a student's mind, secular studies must be approached from a Torah perspective." He gives the example that by teaching history through the lens of Torah, "we can see Hashem's guiding hand throughout time."
Sadly, most of the secular studies teachers in our Yeshivos are teaching from a purely secular perspective, with no mention of Hashem or Torah in their classes. R. Hirsch recommended that Torah observant Jews should primarily be teaching secular studies. Even most of those who are Orthodox Jews teach in a way that is indistinguishable from the gentile and secular Jewish teachers. If they were following or even simply aware of the Hirschian approach, they would certainly find ample opportunity to bring in Hashem's Hashgacha. While it may be impractical for schools to employ only Orthodox limudei chol teachers, I would love to hear that they are occasionally sending in frum teachers to bring out the Torah perspective in each subject.