With disputed I mean mainly that whenever there is a study linked here for example (drug decriminalisation shows benefits) - there is a heated debate about it. And also links shown to other studies. I know that elements of the established medicine in germany for example are highly critical of decriminalisation. So - if something is disputed (rightfully or not) it is not hard to see why it is not allways implemented.

> whenever there is a study linked here... there is a heated debate about it

There are tons of people in this world who don't believe in evolution, but there aren't a whole lot of scientists who doubt its validity - laypeople debating science is worth about what you pay for it.

The only interesting question here is whether there is debate in the scientific community about these topics.