But this mitzvah does tell us something about honoring ones parents--that it is so serious as for the Torah to give a death penalty to one who does not obey his or her parents.
That means Torah considers this mitzvah to be more than just serious. Now we can understand that this does not apply when a parent is telling one to do something against the Torah. But that is not the usual case when children or teenagers rebel.
But what I find interesting is the Torah in general does not command openly about respect to anyone. Respect towards kings, or prophets, or even priests is no where commanded in the Torah.
The only human beings the Torah tells to to respect and obey are our two flesh and blood parents. Not spiritual parents. Our actual physical -in this world- parents.
Why is this mitzvah so universally ignored is beyond me.
There is an interesting idea on this subject from the Naphtali Troup [The green book you see in yeshivas]. But I don't have than book with me now but if you can find it I remember he had some good ideas about this subject.