So much Whig historiography so far.
What actually happened was that crime skyrocketed during the 1960s. This lead to the government trying to respond with restrictions on drugs. These restrictions were very popular with voters. Crime peaked in 1993 and so did public opinion against marijuana. Since crime has plummeted voters are now much more concerned about other issues and people have become more open to legal weed. If crime goes back up, much of the support for drug legalization will evaporate.
The only U.S. connection between crime and Cannabis started when it was banned in 1937. Then people began going to jail for this victim-less crime. Any connection between crime fear mongering and Cannabis opinion is engendered only in the reefer madness mindset and associated propaganda.
But then again sheeple will be sheeple, so from a strictly opinion-based standpoint, there probably is some unfortunate truth to your idea.
The intensity of criminal prosecution against weed in the sixties wasn’t so much a reaction against increasing crime levels as it was an attack on certain demographics who were considered political opponents of Richard Nixon.