[grasbo]

That is not universally true, even if it may have applied to some parts of the US prison system in the past.

In particular, influential British prison reformers of the 18th and 19th centuries, such as Elizabeth Fry and John Howard, promoted sex segregation as a means to prevent the sexual exploitation of women prisoners. They also pushed for many other reforms to make prisons safer and more rehabilitative environments in general. Nothing to do with patriarchal misogyny.

More recently, the UN's Standard Minimum Rules for the Treatment of Prisoners, first adopted in 1955, states as one of the standards that "men and women shall so far as possible be detained in separate institutions; in an institution which receives both men and women the whole of the premises allocated to women shall be entirely separate". Their rationale was not patriarchal misogyny either, but rather how to maintain a safe and dignified environment for inmates.