This dubious argument has beeen rebutted hundreds of times in FR alone!
Simply stated: Not True.
There. That's better. pot is MUCH more potent today, and pot use does lead to other drug use. That's a FACT. Ask any pot head if they had tried other drugs. The answer is most often "yes". Next, go to the morgue. See the kids on the slab dead from drug abuse. Ask if any of them smoked pot.