The answer to the concern of potential health issue of cannabis legalization is almost always "what about [this other bad product with some common effects], should we forbid it too?"

This argument always sounds like a fallacy to me, as we're talking about legalizing something that was previously not, not the other way around.

I get that the argument might be seen as relativizing by providing examples of legal substances everybody agree today should be legal, but the way this answer (and others) is always presented sounds to me excessively aggressive and non-productive. If you want to make a point, please make it, don't just stop at this absurd proposition.

---

Some people (I'm not even included in that group as I don't really care about this issue) seem very concerned about the global health implications of cannabis legalization.

Instead of aggressively diminishing this opinion with whataboutisms, legalizing proponents motivated enough to answer to this person should IMO better take into consideration (and respect) this opinion.