The vice was the war on drugs that was disproportionately applied to minorities. Legalizing weed is taking one weapon out of the arsenal of the police state.
In other countries it was applied to their majorities (who could be minorities in the US). The war on drugs was not a U.S.-only thing. It was worldwide. Because it was a losing battle (products easier to grow manufacture AND transport, they’ve pretty much all realized it’s a losing battle —with some major exceptions like Japan and Singapore who still take drugs seriously and will incarcerate for small amounts.