It's very hard to see a discussion on this topic that does not miss the true point:
This "conflict" is the fight between nationalist movements (Spanish and Catalan) which re-enforce each other in every turn for the worse of the majority and of the European Union.
On the Catalan side, the Nationalist movement is used by dubious politicians which belong to the richer statements of Catalan society to grab power and "make history". The love of the flag and the dishonest approach to history and current socio-economics of the region are strategies followed by every other wannabe-patriot in the world. The illogical approach to their goals and the complete divorce from reality will likely hurt any further attempts for autonomy or proper independence in the long term.
On the Spanish side, the winners of this conflict are ruling right wing and all the until now minoritary extreme-right movements. Thanks to Catalonia, Spanish nationalism of the worst kind can resurface and perpetuate itself in power. It is not casual that Spanish rulers have been completely deaf to the long standing demands of a large part of the Catalonian population.
The only way the Spanish nationalists win is by having the Catalonians take the most confrontational of the paths: declaration of independence.
The only way the Catalonian nationalists win, is by having the Spaniard ones repress and provide a moral ground which supports their otherwise futile aspirations: break the law.
Whoever the winner of this fight is, it will be a sad day for Europe, because nationalism and national borders will have prevailed and this goes against everything we need to build a stronger and better EU.
The tragedy here is that, in the end, everyone loses. Politicians are not focused on crushing poverty, judges are not working to end corruption, police is not busy catching terrorists. The majority is just watching this sad show, hoping it's over soon, so they can go back to their lives which, by the way, are exactly or worse than before.