Part of what you are saying is misleading for the simple reason that Catalonia does not consist solely of Catalans (i.e. an ethnic group as opposed to just anyone living in that region). It is a part of Spain, and thus people from anywhere in Spain can move there. They did not participate in the referendum with the argument that it was illegitimate.
The closest parallel is probably Quebec in Canada, for what it's worth. Highly contentious. One thing I've learnt is that if I want to keep my friends in these places, I don't mention politics.
But Québec would've been independant if the referendum was successful. Even at 50+1, it is now clear that the federal government would've accepted the results even if they didn't explicitly said so back in 1995. So I think there's a huge difference, considering that in Catalonia the referendum was completely ignored
The Spanish state doesn't make any provision at all for secession or independence movements; it's all criminal. They even have a special court for dealing with these matters. Any attempt to campaign for independence puts you beyond the law.
In those circumstances, it's hardly surprising that independence campaigners broke a law.
The closest parallel is probably Quebec in Canada, for what it's worth. Highly contentious. One thing I've learnt is that if I want to keep my friends in these places, I don't mention politics.