Short term yes alcohol is more dangerous.  But long term pot is.  There are twice the carcinogens in pot than in cigarettes.  If you think cancer rates are high with cigarettes, you'd be amazed at the chronic problems marijuana will cause.  Especially neurological problems after long term usage.  Pot is also much more addicting than alcohol.  Pot is much easier to carry and use than alcohol.  But it can provide a similar effect.
The major reason why I'm in favor of legalizing it is because of the mass usage going on now in the country, and the missed tax revenue from it.  And it's rediculous that so many of our tax dollars go towards prosecuting and pushing people for using it.  The way I see it, we have a lot to gain from legalizing it, but we need to impliment measures to keep it as though it is still illegal, so people dont abuse it.  Just the way americans do now.
The only reseason why I added the government sponsored class and permit, is to make it even harder for younger kids to get it.  I know people will still buy it for other people, but it will be much harder to obtain.
But like I said... even if the government legalized it, the major problem is that I believe employers would still continue to conduct drug testing.