Without doubt there would need to be regulation and what not but alcohol can take some people to dark places too. The problem with ganja is that there is a lot of legal synthetic weeds out there which blow the head off you. I smoked one before and I could not believe how much I was tripping off supposed 'legal high'. They're so powerful and some of them actually look like grounded up weed. They're the dangerous ones as they're mixed with countless chemicals and HAVE resulted in deaths.
However, like everything else, some people abuse the system and what should be considered a luxury. I've got countless memories I will never forget, half down to the absolute laughs you get from smoking. But as said, if it was legal it would give people an excuse to abuse it and sit on their fat plum and smoke it all day long. Those lot give weed a bad name.