The state of Saxony-Anhalt has said people who do not recognize Israel's right to exist cannot become naturalized citizens. The eastern state's interior minister said Germany's other 15 states should take similar steps.
I did specify world view, did I not? A credible commitment to the rule of law, democracy, secular politics, and to the rules-based international order would be a start. I don't think we should award citizenship to anyone who can't even make lip service to these principles.
edit: smart selection process on the part of that German state actually. Screening out people who would deny Israel the right to exist probably also catches a lot of those who would fail some of the above requirements.