Honestly, it's probably mostly just a tourism thing at this point. Most of the Dutch people I know tend to not care about weed but they see coffee-shops as a thing for tourists or international students. If you're a regular user in NL, then you have a hookup or grow your own plants.
Also, anecdotally, I can smell a lot less weed in Amsterdam than when I've caught a wiff of it in the US. You have to be walking right by the shop before you smell it usually. I'm not sure if this is a local regulation or what, but I suspect the Dutch would be much less tolerant if their public spaces reeked 24/7 (but no worried about the dog poop on the sidewalk)!
Also, anecdotally, I can smell a lot less weed in Amsterdam than when I've caught a wiff of it in the US. You have to be walking right by the shop before you smell it usually. I'm not sure if this is a local regulation or what, but I suspect the Dutch would be much less tolerant if their public spaces reeked 24/7 (but no worried about the dog poop on the sidewalk)!