[DanBC]

It's a bad thing because it leaves space for criminal gangs to make money and does nothing to tackle any harms that result from drug use.

Most people who use cannabis will experience no ill-effects. Many of the harms are reducible - use a vaporiser at the correct temperature rather than burning the plant material for example. A few people will experience ill-effects. Providing help to those people through public health measures is more effective and cheaper than targeting them through criminal justice systems.

> fairly addictive

Citation needed, unless you're misusing "addiction" to mean "habit". Cannabis is not physically addicting and the psychological addiction appears to be weak. There is some element of habit associated with it though.