That's your opinion. Mine is different. Invoking the principle of least privilege, if some piece of information on your personal life is of no use to the point you're trying to make, why reveal it? You gain nothing, and there a chance (though remote) that it will be used against you at some point in the future.

A thought experiment: suppose you were an alcoholic... would you admit it on HN? If not, why's that so? Is it illegal? Are you a politician? Maybe it's because of the social stigma associated with it. Well, guess what, not everyone shares the same values you do and in some more conservative circles, smoking pot would carry a stigma as well. That could harm you when looking for a job, for instance. I have seen that happening.

Maybe I am paranoid, but better safe than sorry, right?