Why do people smoke marijuana?

i just dont get it. as a mother i know how bad it is. it is one of the most addictive and deadly substances on the planet! i just dont get it. its as addictive as heroin and 1000,s of people die every day from it but people still do it! if i found out my kids stoned or found oout they have in the past i would ground them and never let them go anywhere or do anything until they were 18. of course i actually care about my childrens lives unlike those druggie potheds