There are some exceptions and many different divorce laws, but the example obviously should be taken in a spanish context, and not trying to suggest that Catalonia (typically represented as the wife) was cheating to its partner Spain (typically represented as man and violent abuser) so she "has the right to go". Would be against their own discourse.

http://www.vozbcn.com/figura/2009/11/20091127nou.jpg

"Shouldn't your wife be allowed to divorce from you if she wants" with an implicit (because you abused it) would be, on the other hand, an extremely rude example. I don't think that this passive-agressive possibility was even in the mind of the people posting it.