I think the feminization people are talking about was more in the acting style that became prevalent after the war. During the making of ‘Red River’ in 1946, John Wayne thought that Montgomery Clift was ‘weird’ and ‘fruity’. That sort of internal method acting as seen as effeminate.
My husband is a film teacher and he shows “The Heiress” to his class to demonstrate 3 styles of acting:
Ralph Richardson (British theater acting)
Olivia DeHavilland (great Hollywood acting values)
Clift (Method)
And they all come together!
The Duke was right about Montgomery Clift.