Laws mandating seat belt use do indeed increase seat belt use which, every year, demonstrablely saves thousands of people from death in the US and tens of thousands from very serious injuries.
Most people regard saving lives and reducing injuries as a good—not only for society, but also for the affected individuals.
Laws forbidding smoking pot do not seem to reduce pot smoking to any significant degree, but do result in thousands of deaths from drug turf wars—just as happened with alcohol prohibition. Such laws also adversely affect millions of people who are prosecuted for their involvement with pot, divert and corrupt law enforcement, erode civil liberties and cost the taxpayers a tens of billions of dollars every year.
Most people regard producing excess deaths, ruining lives, encouraging corruption, reducing civil liberties and wasting resources as morally bad-- not only for society, but also for the affected individuals.
The 48 year old Cuban embargo has obviously not worked—unless one wants to credit the embargo for Fidel Castro’s recent removal from power. The only adverse effect I can imagine from a lifting of the embargo is that the weight of the millions of American tourists would who visit the island may cause it to sink.
If that problem were avoided, Americans would have a new and interesting place to vacation and the standard of living of Cubans would rise. How can that be bad?
There’s no evidence that laws against gay marriage have produced any good—for individuals or society. Such laws, however, clearly adversely affect a significant percentage of the population. How can it be good to hurt some people for no demonstrable reason?
So: these changes are very much for the good.
Bob