Why was the French writer Georges  Simenon so famous in Soviet Union? (No, really, why? I don't understand)

Sometimes, while working, I listen to old soviet radio plays. In the Soviet Radio there were a lot really cool genres from criminal book to sci-fi. It sounds likes audiobook but with intersound and several actors. And really famous actors gave their voices to really famous characters from the world treasury of literature.

And I found a lot plays with French detective Megre as a main character. I tried to listen these audio and, You know, I found these books very bored. And as I remember the Simenon's books were sold all over the country. But why? A mistery.