This is a term used to refer to, among almost nothing else,
pornography. It is
misleadingly titled in an attempt to garner
respect for something few would
admit as
deserving respect.
The problem, much like many other things, is that governments gets to decide arbitrarily what is right and wrong, not the individual. These morals are imposed by law on a society based on religious beliefs rather than scientific methods.
Other arbitrarily assigned adult rights include representing oneself, signing contracts, and controlled substances.