I find that not entirely contradictory, both are tools of societal control. From a perspective of power, whether you legalize marijuana or not is not a question

I find that not entirely contradictory, both are tools of societal control. From a perspective of power, whether you legalize marijuana or not is not a question of personal liberty but what is of greater utility to your immediate political goals. I think it is an open secret that the 1960-70s criminalisation of drugs was not really because of concern for the health of the users, but because it was an effective way to suppress and ultimately eliminate the threat of the emerging counter culture. Maybe in light of growing inequality and youth unemployment marijuana is seen as one of the diversion tools to prevent the poor from taking political action. Especially because it has roughly the intended effects, when used regularly. Note that it is not entirely out of the question that people in power think that way, for example the 60-70's were perceived as a "Crisis of Democracy" in parts of the establishment.