The worst thing about weed is the pretentious weed babies who take their first hit and are like "greatest thing ever! smoke everyday blaze it 420Xx", "cured my friends diabetes cancer! legalize it all!", and "stupid government and tobacco companies are oppressing me! legalize!".
I don't know if weed is bad for you, but I do know a lot of living stereotypes of people who talk slow and relaxed. They don't seem like very productive people.