Fuck no.
Lets say McDonald's. Everyone claims that it's a huge gateway to obesity, but nobody forces anyone through the drive thru or into the doors. It's a self choice.
Nobody forces anyone to spark up some weed, if so you're a lucky fucker. Weed isn't addictive and I can say from being purely a stoner for a while. Popping pills was a decision I soley made on my own and is the same for anyone else. Now if someones starts on some hard shit, though they weren't forced to take it, it could surely lead to a gateway to wanting to find another drug to make you higher, I know.