R’ Eidenson, a psychologist with a blog called Daas Torah, reported that he often had young people come to him with “psychological” problems, which he realized were in fact hashkafic problems. That is, they had trouble believing in what they thought they were supposed to believe, and felt bad about that. In most cases, however (if I recall correctly from his description), he discovered that the patient’s beliefs were actually consistent with valid hashkafic opinions expressed by rishonim or acharonim, even if they weren’t the most commonly-taught opinions. For that reason, he wrote a book called Da’as Torah, which compiles the wide variety of historical rabbinic hashkafic opinions on a variety of subjects.
In my opinion, kids at frum schools should learn a variety of hashkafic opinions and perspectives, including both more rationalistic and more mystical approaches (different forms of chassidus, mussar, R’ Hirsch, R’ Kook, R’ Soleveitchik, etc.). The way I see it, there is something out there for everybody, and some people will have little enthusiasm for Torah and mitzvos if they are only exposed to one point of view (rather than exposing them to, and letting them choose among, various (kosher) options).