Seems to be a deep instinct in human beings for making everything compulsory that isn't forbidden.
Robert A. HeinleinThe Ten Commandments are for lame brains. The first five are solely for the benefit of the priests and the powers that be; the second five are half truths, neither complete nor adequate.
Robert A. HeinleinWhenever women have insisted on absolute equality with men, they have invariably wound up with the dirty end of the stick. What they are and what they can do makes them superior to men, and their proper tactic is to demand special privileges, all the traffic will bear. They should never settle merely for equality. For women, "equality" is a disaster.
Robert A. Heinlein