Eh... To be honest, considering something such as alcohol is legal everywhere, I don't see much reasons for marijuana to not be. Listen, I'm a 18 year old that have smoked this and haven't really felt any bad effects (yet, I suppose), but when it comes to alcohol, it's effects occur quite fast for something so legal, and I don't really see anything good coming out of it. That is, considering you're addicted, which most people aren't.
It have to be legal here in Brazil, simply because it's the open road for other drugs. EVERYONE starts with it, and the number of people that go to jail because he was catch smoking marijuana is simply ridiculous for something so... Small. But you know why they have go to jail because of this.
Now, if I want to be legalised? I don't. It smells bad, I don't see anything worth my money on this stuff, and chldren nowadays are pretty much messed up because of alcohol, yet there'll be another legalised drug for them to use. But considering those are most personal opinions, I wouldn't take it much serious. Marijuana have to be legal because the effects would be "less worse" than if it wouldn't.
Either options are bad, but I feel like making it legal would be better than not making it, even though it's not my desire to have it legal.