having said that, you normally try what once worked in some way or form. So franco activist were against Madrid and catalonia, pre-franco times there was some animosity too but it was about anarchism-socialism-liberalism-authoritanism more than anything else..

It is a clear example of Levi_Strauss ideas, take a basic myth and make simple logical steps to adapt it.

So the basic mythology has history, the present virulent form is new.

A pleasure

I therefore claim to show, not how men think in myths, but how myths operate in men's minds without their being aware of the fact. Levi-Strauss, Claude

Sociologically, Madrid's arrogant view as the unquestionable center of power is made up by large numbers of poverty-stricken rural migrants that have worked hard (in appalling conditions during the dictatorship) to reach a comfortable financial position in democracy, without equally improving their educational level.  These two-three generations are easy prey for the PP pathology that repeats 'Catalunya has it easy with 'our' money and that's why you can't have more ... services'.  

Catalunya is prosperous and has an image of being entrepenurial, persistent, productive and innovative, but not submissive.  What's not to envy and reject?  

Add to that the Catalan nasal speech and entonation that can be spotted immediately, plus their demand for equal political-economic treatment and you have the perfect 'other' in a knee-jerk brain.  

Our knowledge has surpassed our wisdom. -Charu Saxena.