It is mostly political...
The real reason behind those languages being still in use is because of political reasons. Spanish is called Spanish (Español) everywhere *except* in Spain. Also, only Castellans will call themselves Spaniards (Españoles) as well; Asturians are Asturians, Gallegos are Gallegos (and oh dear, the jokes on the "Gallego idiot" are infinite!); Catalans are Catalans and Basques are Basques. Those with their own languages use them as a differentiator stating "we ain't Spaniards!".
I still remember one friend searching info on the Barcelona University and got slammed with that university's Catalan-only website. Ow!
That said, it does seem to be the same case for Welsh, anyone remember those super-duper-long towns which were named that way just to fuck with English-speaking people?