You are pulling the same tactics as the Christian moralists in this case: fudging the issues. The Pondoland story is to do with the fact that at present thousands of subsistence farmers regularly have their livelihoods destroyed by SAPS squads burning their cannabis fields. It is nothing at all to do with taxation. Won't somebody please think of the Pondoland farmers' children?
The taxation issue has to do with regulation of the drug (and thereby the restricted access of minors), as well as providing funds for the TINY MINORITY of regular users who might require medical or psychological help (as per the Portuguese case).