No, we shouldn’t. you may be seeing what you want to see in this matter. From what people have said, Catalonia was a center of Left-Wing militancy in Spain for quite some time-the independence parties are all or mostly freaking Leftist themselves, and they may desire a independent Catalonia be part of the EU anyways.
What I see are people who want independence; self determination.
‘Lefties’ generally want a strong, centralized power. Control of the people. Not sure these people are cut from the same cloth as our own liberals.
Regardless, they want to call their own shots. Did we not want the same back around 1776?
Which would make the rest of Spain more right wing after the separation. win - win.