Earlier quoted context omitted.
Right to exit is an important foundation of legitimate rule. Plato's Crito has Socrates make the point that, even sentenced to death, he was bound to respect the laws of Athens as he was someone who had made the voluntary choice to remain in the city all of his life until then and under those laws.
Right to exit is an important foundation of legitimate rule. For individuals, sure, and I'm quite sure Catalonians are free to leave Spain and go somewhere else.
Now what is the right of the group? What rights does Spain as a nation have and what right to do the Catalonians have as a people, and where do such rights come from?
The answer to each question will have a lot to do with how much you love each one.
Someone who hates Spain and the Spanish would certainly suggest that their course is to be a grubby landlord, trying to get every cent out of a tenant before kicking them out the door. Someone who loves them would hopefully never think of them as the sort of nation that would wish to impose on a free people or steal anything from a people, especially not land or property.
Lovers of Spain, properly, will think of their rights as rights of attraction, and free association, and from the governors to the governed. Haters will think of the Nation's rights as something to be imposed, and their duties as something to be extracted from their subject peoples.
What do you think of Spain? Is it love or hate?