All I tell people is look:

1. Marijuana is less additive and less harmful to your body than alcohol or cigarettes.
2. Except for the tar (which could be fixed by a vaporizer) there is nothing harmful entering your body.
3. If people used it responsibly, i.e. no driving or heavy machinery, or better yet, only smoking in your homes and in hash bars... because if america had hash bars it would be awesome and noone that didn't want to be around smoke would be bothered.

I have always thought that hash bars along with no smoking outside laws could make smoking something that would be good for us stoners, but not effect the people who don't smoke.