Language is powerful. The word 'user', when employed to describe someone who consumes marijuana, stigmatizes their legal activities and marginalizes them as a human being by associating them with non-legal drugs.
Just as regular people don't 'use' alcohol, or 'use' prescription medications, consumers of cannabis products do not 'use' drugs. They enjoy, heal, create, support, unwind, love, connect and savor - but they do not 'use'.
History is replete with examples of the power of language: to many Caucasians, 'black power' was threatening; 'civil rights', less so. As a society, we progress when we allow our language to shape our debates positively; and since the tide of public opinion is firmly in favor of further legalization, this change in language cannot come soon enough.