Yes. That's ultimately why the Cataluña thing is a paper tiger issue: Catalans are too rich and too soft to really break away.
I'm not saying they're not allowed to have grievances, nor that they don't have any legitimate ones, but these people live extremely comfortable lives in a highly (_highly_) autonomous part of a relaxed, modern, Western nation. The independence stuff is mostly posturing. There's a good saying in Spain about this these days, roughly translating to "Catalans don't want to secede; they want to be secessionists."
It's cosplay revolution, and the rest of Spain has a good case for losing its patience with it. They want to break away, but no, sorry, the rest of the country is not allowed to have a say in the matter? Some Catalans (a minority, everyone seems to forget!) want their own country, but they also want it to be handed to them voluntarily by their "oppressor" in Madrid? They want to commit crimes but they expect not to be sent to jail?
At this point I'd almost be grateful for a Catalan Lenin of some sort; at least then we'd know there's an adult in the room.
> legally speaking
I don't see how any of these things matter.
If there's no right, if there's no legal means, then wage war. Die trying.
I'm not suggesting I support either position, but pointing out that, ultimately, laws and opinions don't matter.