I don't drink, smoke or do drugs of any kind and my wife says I'm too darned old & foolish to chase loose women, but I honestly can't see any problem at all with some guy smoking a joint. I've known lots of guys over the years who enjoyed a puff now and then and never once did I see any of them cause problems because of it.
So many folks seem to think it's perfectly fine and acceptable to have a beer or glass of hootch but somehow a joint is evil.
Make it legal, tax it like booze or smokes and let folks enjoy it.