I was looking over Amanda's posts on the way Date Night sometimes gets viewed as part of the work that married people do to maintain their marriages, rather than a fun thing to do with somebody you like. She cites Laura Kipnis, who "talks about the Protestant work ethic and the American fear that there’s something immoral about having too much fun."
This is a big problem. A society where fun was regarded as a genuine social good worth promoting would be, well, a lot more fun. The issue of recreational drug use is a biggie here. And it's not just in terms of fun and relatively harmless currently prohibited drugs like marijuana. (If marijuana is legalized, I want to have potlucks where all the guests get high first and then eat each other's food, which will taste extra super great in the way food does when you're high. At the last party I went to in Austin, I was watching the ceiling fan spin as I ate my friend Jenn's raspberry lemon cake, and it was like my mouth was full of sunshine.)
To my knowledge, pharmaceutical companies aren't currently researching any new, purely recreational drugs. Of course, there's all those drugs that help dudes get erections, but they get away with those because they can be justified on the basis of fixing a medical problem, not on grounds of fun sex. This is a big loss. I'm sure that the American pharmaceutical industry could come up with a bunch of fun-causing psychoactive drugs that would have minimal side effects. There's definitely a market for them, and if the FDA screened them properly, we could get all kinds of good and harmless stuff. But the fact that people would enjoy these drugs isn't taken as any sort of point in their favor, and I'm sure Big Pharma avoids working on them because of the certainty that the sweet fruits of their labors would immediately be banned.
There's a pretty good misery-preventing justification for this sort of research too -- if Big Pharma was allowed to sell well-tested, safe, non-addictive euphoriants, they'd cut into the market share of more harmful illegal drugs. But the biggest reason to allow these drugs is disabled when you don't let people give fun-based arguments for things.