I'd rather marijuana be legal than alcohol. It's certainly less harmful to the users and those around them than alcohol.
There is no harm in responsible use. The pint of Guinness I occasionally have with my supper is not hurting myself or others.
Furthermore, prohibition has been shown to be ineffective and harmful in and of itself.
Laws are meaningless without enforcement. And at least in Vancouver the police don't give a crap. I don't know anyone who's even been fined for it. They'll go for grow ops, but not individuals unless you're really being blatantly stupid about it.
I wouldn't risk my career on it. A criminal conviction means the loss of my security status, my professional designation, and my job. It would also be the end of my ability to travel freely, as a drug conviction would make it difficult for me to visit other countries. Japan seems to be especially picky about that.
Fixing the law is worthwhile. Arbitrary enforcement is not a real solution.