@Zardoz,
Look Zardoz--if you define a cult in a certain way and that definition allows you to say that the Catholic Church is a cult, then it is a cult from your point of view. Tautologically.
It being a cult does not undermine the wisdom or otherwise of its teachings on sexual morality which are what I think you actually object to. I don't see any other reason why anyone would object to one cult's ideas on other matters more than to those of any other cult.
The Church was invented because all other known cults had proved to be a dead end which cannot yet be said about the Church.