This isn't limited to "journalism". People have been trading sex for anything advantageous for centuries. Basically any personality type with a predilection for impulsive behavior would have done it– it's not as if Hollywood started it.
The 1970's. Just think of the conventions and trade shows in the 1970's, especially pre-AIDS. "Hey, we're in Kansas City, it's late, I want to make this sale, and the liquor is flowing"– It was the Wild West.