> From the standpoint of "hard to ban what's used by a large part of the population" this does justify legalization indeed.

I think they meant more that the negative effects don't seem that big because most people are ok even with such a large proportion of people already being experienced with it.

> triggered by the parent's comment weird theory that "cannabis was only forbidden because of criminal big pharma".

I don't believe it was either but I'm not sure your counter evidence really works. The science that you alluded to about long term effects all significantly post-dates the ban so couldn't have played a role in it.