The NAACP was formed in 1909 by mostly white people. Hubbard was born two years later, in 1911 (my mistake above...). The NAACP won the right right for African Americans to serve as officers in WWI. This happened when Hubbard was an infant/toddler -- so there certainly were some visionary people around at that time. WWI ended in 1918. Hubbard was 7 years old.
Women got the vote in 1920. Hubbard would have been 9 years old -- still a child, hardly of an age to be a mover and shaker in the culture, but he would have grown up in a world where women had full citizenship.
Usually the cultural influences that most shape a person's character are those that one encounters in late teens, twenties, early thirties.
The Civil Rights movement was active in USA as early as 1954, when Hubbard was doing much of his writing about the inferiority of other races and cultures. Obviously he wasn't part of that movement, but plenty of others of his generation were.
Hubbard was expressing his adult views during the time of McCarthyism in USA, late 1940s and 1950s -- not exactly USA's finest hour. His anti-communist sentiments are threaded throughout his work. His progressive cultural and creative contemporaries were the writers and artists of the Beat Generation, who changed the culture while Hubbard was stuck in the past.
"Political correctness" is a term often used by bigots to make little of people with progressive ideas and beliefs, and to assert their right to their reactionary views. It has little or nothing to do with actual human rights or real cultural progress.
Thank goodness Hubbard never actually achieved the level of religious and political leadership in this country to which he aspired.
As I wrote earlier, his cultural opinions and views that are threaded through his work show that he is not at all a man of "vision" -- in fact, he was the opposite.