For those of us who see legalization as a social justice issue (i.e., recognizing that certain minorities have historically borne the brunt of the "war on drugs") legalization, and expungement, in itself is a truly worthwhile goal.Without homegrow it's almost not worth legalization.
I too would like to see the law be liberal in terms of personal freedom. Limits on plants, limits on public consumption, limits on private sector discrimination: these are all also very import aspects of legalization. But even if the first version of the law isn't perfect in these regards, to me, it's better to get legalization on the books and remove cannabis as a political tool wielded by regressives against vulnerable communities.