I think this may be a case of 'wait and see'. As Uruguay were mentioned in the link as the only other country to have done something similar, i turned to Google for some info. After a few delays, this move was implemented as recently as 2017 so there probably hasn't been enough time for the powers that be to assess what difference, if any, this has made to crime figures, health, extra revenue from taxes, etc. There they have a system whereby those buying the drug legally from the 16 authorised pharmacies must be registered, Urguyan nationals, over 18 and are allowed just 40g per month. ID is confirmed by fingerprint scanner at the point of sale. An interesting and brave move by the Canadians.