Well, yes, in the abstract it was a personal choice, but, in fact, at that time, not marrying was almost not an option.
When I was in grade school, probably 80% of the teachers were unmarried women in late middle age - "old maids" they were called. They seemed to live nice lives. In spite of their teacher's salaries, they all drove nice cars. They hung out with each other and traveled all summer long. But I think of the things my mother used to say about them. Of course, to their faces she was never anything but polite and respectful, but she used to say that they were defective, or abnormal because they weren't married and didn't have children. And I suspect her attitude wasn't uncommon. They were outcasts - serving a worthy function as teachers, but otherwise dismissed.
Unmarried men were known as "confirmed bachelors" and were also highly suspect.