Everything is based on strength. If the Catalonians are stronger legally, or sufficiently strong physically, there will be change. It will be based on compromise.
The point is, governments are changing because the crooks in government are making mistakes that are harming the people.
I foresee and expect a banking collapse, which will bring on a governmental collapse, worldwide. The face of the world will change. It won't only be Spain.
Right now, there are States in the USA that are looking at the idea of secession. Texas is one of them. And it is built right into the contract Texas has with the U.S. They can legally pull out if they want.
Government speeches, and the media, are full of propaganda designed to weaken the thinking of people who seem to be determined.