“Understand that your teacher has ulterior motives into creating separation between you and your parents.”
I agree with this statement and will elaborate according to my own point of view.
The shul Rav is a spiritual guide whose duty and desire is to take care of his constituent families with halachic and other spiritual advice. He is in it for them, not for himself or a given institution, and his decisions take many factors into account.
The “teacher” is charged with a very specific agenda, to inculcate the students with a very well-defined hashkafah which views itself as the only “right way”, and rejects other hashkafahs as not legitimate.
The teacher is therefore suspect of ulterior motives, namely, forcing the the student into the mold of the school’s hashkafah at the expense of the parents’ hashkafah.