Are you suggesting that caffeine, alcohol and nicotine are not also damaging to the human body? Or are you retreating into "it's legal therefore we're okay with the damage it causes" territory?

X can cause people to do really stupid and dangerous things.

This is true for all manner of X which induces feelings of alertness, happiness, and confidence. Alcohol can cause people to do really stupid and dangerous things. Caffeine can cause people to do really stupid and dangerous things.