Europe is more bureaucratic. You have to register with the government to say you host user content and respond to abuse reports, and then respond to abuse reports, and you're shielded.
Compliance certification costs money - lots of it. The laws also require proactive scanning of uploaded material, not just responding to complaints, and require a person to be declared liable for mistakes.
Gone are the says of paying a couple hundred a year for a host and a vBulletin license. The new costs are many thousands plus permanent liability, and no thanks - that's way more than I'm going to do for a group of enthusiasts online.