They've done more than that they're keeping the rest of world's potheads out and the crap they bring in their train. It will definitely have a positive effect.
Yeah, until the stoners figure out this brilliant idea:
“Hey, let’s stand in front of the coffeeshops and like have someone go in and like buy the stuff from us!”
Then the Dutch tourist with a card will figure this brilliant idea out:
“Hey, I can like buy a gram for 5 euros and sell it to these guys for 7-10 euros! I do this a couple times a day and my gram is paid for!”
Nah, that would never happen. Black markets don’t get created when there is a demand for something...