Just a bit more on Catalan politics. The thing to understand is that in Catalonia the middle/professional classes are overwhelmingly Catalan linguistically and Catalanist politically. Castilian language (and, to some extent, identity) are present in two very diverse population strata: a very small numerically (and, hence, electorally insignificant) aristocracy and the working class (which is, to a not insignificant degree, ethnically Andalusian).
For Catalans (i.e., the Catalan middle class) PP is a foreign party, as relevant to their political choices as the British Tories - except, perhaps, there is less hostility to Tories
) PP in Madrid stands for everything they despise - mainly, the strong unitary Spanish state. Probably, some figures in local PP would like to mitigate this image, but they are not strong enough either locally or within the national party.
As for the working class, PP, a quintessentially right-wing party, has no appeal. PSC (the local PSOE affiliate) might be Catalanist - but, at least, it is a working-class party.
There is another, historical aspect to this. PP is, fundamentally, a "Franquist" party: perhaps, not formally, but in terms of identity of many of its adherents - it's the party of the victors in the Civil War. It's not that Catalonia didn't have those who actively collaborated with the dictatorship, but, in general, they tended to find their political home in the U wing of the CiU. Unlike those with similar past in Castile, by now they'd rather forget about their own history: it's easier to think that they always have been, at least at home, good Catalan patriots. And, of course, workers feel little attraction to their historic enemies: their party is PSC, not PP, however upset they might be about the Catalanist policies of the Autonomous governments.