You are inhaling dead plant matter, so i think it isn't any better for your lungs. But I might smoke one joint a night, and my friend will have a cigarette every 2 hours.
Also I'm 29 years old and neither a student or unemployed. I think i do alright for my self with a annual salary of over a hundred thousand.
You would be very surprised on who use the 'drug' frequently. It is taboo, like talking to people about sexual fetishes. People that smoke pot are usually paranoid and avoid talking to strangers about there illegal activity.