I know plenty of people who have been smoking for 40+ years but they are very intelligent people who know how to handle themselves. Marijuana doesn’t turn intelligent people into imbeciles. It can however, turn imbeciles into weirdos who don’t know how to handle themselves.
Yes, the evidence appears to be in, that certain segments of the population go psychotic under the influence of weed.
But that's no reason we can't make it available to everyone, right? What are a few random murders here and there compared to everyone's need to get high?
Most, however, are bad drivers.
All lead miserable lives inside their heads.