There are huge social, psychological and emotional components to human sexuality. The physical aspects are just one piece of the equation.
There are consequences to making it all too prosaic to have everything on display and they aren't all positive by any stretch of the imagination.
I have spoken to someone who went to nudist colonies. He told me outsiders always imagine it's all sex, all the time but it absolutely is the opposite of that. Most people aren't especially sexy when running around naked to begin with and when you normalize nudity, it further reduces the sexual element.
Just because you aren't familiar with the literature doesn't mean I'm making stuff up here.
Some of the most shocking and suspenseful films ever made had little to no nudity or violence. They did so through good writing and production. Throwing a bunch of blood or boobs on the screen is cheap and easy and attracts like-minded audiences. Making quality entertainment is hard.
Also, thinking that blood and gore and nudity never existed in entertainment before the modern age and that the "old" values were puritanical is simply false. Shock value has existed as long as there have been books printed, movies made, and photos captured. The things published today have nothing on some of the illustrated gore from the 16th century.
I would prefer entertainment to be more entertaining by simply viewing sex and nudity as less shocking.