It might be fine at low usage levels. But, I have known a few heavy users who where harmed by it. I don't expect being a minor fine will have a significant effect, but it is likely to discourage some people which IMO is a good thing.
My point is that all drugs have risks and harms associated with them. Criminalizing them in anyway is the wrong way to address that (and it's historically never been the real reason for doing so -- it's been about oppression of minorities and dissidents).