What is asserted without evidence can be dismissed without evidence.
I've read the exact opposite is true: that many in Amsterdam have wanted to revoke the permissive laws, because it attracts a lot of, basically, problem people from not just all over Europe, but the world.
https://www.reuters.com/article/us-netherlands-drugs-idUSKCN1VI1OJ
"Long famed for its casual attitude to marijuana use, the Dutch capital Amsterdam says it now has a serious problem with hard drugs that has brought increased violence and corruption at the hands of “hustlers, parasites and extortionists”."