Smoking dope is certainly no more harmful or dangerous than drinking booze, and I'd say less so (people on weed tend not to get into fights as easily, IME). Does this mean it's harmless? No. Does this mean it should be banned? No. While people I know thought dope was strictly harmless at one time, they basically abandoned that idea after they left high school, and grew wiser in the ways of the world.
As for the "dope is as harmless as food" strawman you're beating on... guess what? Food used in certain ways has enabled genocide (cf- Ukraine in the '30s). Should we ban food distribution systems? Baseball bats can be an afternoon's fun at the local park, or a night's terror at the same park after dark. Should we ban baseball bats? Beer can be fun with a barbecue, or a life-destroying drug when used all the time. Should we ban beer? Weed can be fun used in moderation, or something that leads to someone sitting around the house all day unbathed. Should we ban weed?
As for your personal experience, you'd probably be surprised at the number of people here who've smoked dope at one time, or even do so currently. If the stats in the general population hold true here, over a hundred of the people who've signed up have smoked dope at one time, and probably thirty or so do so regularly.