What should we do about alkies whose bills we pay - ban booze? (Free clue: a responsive reply will be either "yes" or "no", not a diatribe about demon rum.)
And this is exactly what I mean. You are offering the "Because Alcohol is bad, we MUST legalize pot" argument, which is both a non sequitur AND a fallacy of tu quoque.
Bad behavior from one group of people does not make more bad behavior from a different group of people acceptable.
You are saying "Because they get away with it, we should too!" Which is nothing but a whiny spoiled brat argument. Indeed, the "He did it too!" is about the most childish thing you could say, and you wonder why I don't take you seriously.