They think that prohibition is merely a failure . They do not understand that it has exacerbated the problem that it was intended to solve. This inability to grasp the concept of marijuana prohibition as counterproductive is an example of the failure of critical thinking caused by our own Doublethink. Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them. These anti-prohibitionists actually hold two contradictory ideas at the same time.
Marijuana prohibition is both a worthy cause and a failure.
There are people who are so convinced that drug prohibition is a failure that they favor the legalization of drugs generally, but they still look with disdain on the users of marijuana and the supporters of medical marijuana and hemp. It is all rather beneath them. Also there are people who have decided that some aspects of marijuana prohibition are failures and favor just medical marijuana or hemp. They have been conditioned to think that the people who agree with them are bad and the people who have been lying to them for decades are really good. If someone has been conditioned to hate the enemies of Big Brother it is very difficult to stop hating them and admit that they were right all along.