It's odd to think that quite a few of the finest crime writers were actually publishing in the twenties. How did they get it right so soon? I like the Sherlock Holmes stories, but "A Study in Scarlet" is a big old mess. But Sayers, Christie, Wodehouse, they're all just BOOM, on target from the start.
...and now after all these decades and all the good examples out there for people to learn from, almost nobody can write great, memorable crime. I suppose you could say that those early days was when education had a much stronger philosophical foundation than it does today, and perhaps that makes a difference.
Possible. Of course, clever women have a few more career options now than then. Maybe it's just that so many books are published it's hard for any two people to discover the same outstanding crime story.