A bit of an explanation is needed.
Like it's said in the article, I live in a border town which has to deal with a lot of drug tourists. That isn't really much of a problem, unless you live near a coffee shop, but,
1.) coffee shops aren't open 24/7
2.) Coffee shops are generally more expensive than street dealers
Tourists with limited amounts of money and tourists visiting when the coffee shops are closed are in fact fueling criminality. When I go to my own train station with a camera, I'm nearly always asked if I want to buy some pot by kids that should be in school.
Also keep in mind that the sale of cannabis is still illegal in surrounding countries and that a lot of tourists buy cannabis to sell in their own country. Since they officially can only get 5 grams per coffeeshop & since they'd have to hop from coffeshop to coffeeshop to get more than 5 grams it's usually easier to buy larger amounts from street dealers.
Since cannabis is actually grown in the Netherlands these days (15-20 years ago we still imported most of it, because we don't have the climate to grow it), usually in abandoned factories & houses and since most dealers (& their bosses) usually stay close to their source of money, the amount of dealers in border towns has skyrocketed. Combine that with the EU's open border policy & once again with the unwillingness of our neighbors to adopt our policy, has left us in this situation.
Still, since the coffee shops need something to sell & since the indoor plantations won't go away, I doubt it's a solution.