Drunks are much worse that pot users and they are doing much more damage to their health. When Pot becomes fully legal, I suspect that doctors will advise their beer/liquor using patients to switch to Marijuana for health benefits. No calories, no liver effect, no possibility of overdose, just a pleasant high.
You can get a lethal dose of alcohol for about $20 and consume it in one sitting. There is no way to do that with MJ.