How?
Stripping away all the justified opposition to prohibition, it’s really not good for most people to smoke weed everyday. Pointing out any potential harms became deeply uncool. It’s not difficult to imagine people probably smoke weed regularly as a result.
This is what conservatives have been crowing about since the 40/50's when black music started dominating the airwaves. It's a really old argument that is literally moral panic with no proof. I thought maybe you had some new thoughts to add, but you don't.
Of course we don't even play 90% of that stuff any more because any radio station would be cancelled within five minutes and not by conservatives.