Well, it certainly is fun and a good cardio work out.
However, there is a good biological reason why we don't ignore each other for 90% of the year and screw like rabbits the other 10%.
Every time a couple have sex, they release oxcytocin. Highly addictive, highly pleasurable, and designed to make the male stick around to help raise the kids. Yes - sex addiction is a thing - oxytocin is more addictive than smack. Makes sense, given a long development period after birth.
The only comparable mammals with the same length development period are whales and elephants - both strictly matriarchal societies and both of them a heck of a sight bigger than humans, with the females usually (not always) being bigger than the males.
It's a way of protecting from a slight defect.
Now as to the government subsidizing it - dumb idea. Though if they could tax it, you bet your ass they would.