Has the battle been lost?

[Torchwatch]

I read a science fiction story some years ago about a grey future Earth in which very few people had jobs and lived sad unfulfilled lives.
The main character was a police detective investigating why so many people were disappearing. Someone had built a time machine and could send you back in time, to any time you chose but you could not return.
One character chose a time when fashions were modest and restricted but secretly behind closed doors a lot of free sex was going on, but after only a few years the restricted fashions would be discarded and young people would suddenly feel free to display their bodies.
History and fashion are constantly changing, wait a few years and the currently repressed fashion influences will fail and n==men will get more freedom.