Apologies flamejob, I misread.
The point being if you disrespect the language, you disrespect the culture as a whole.
As, an assumed, native English speaker, do you think it’s a good idea to learn Castellano or should the petty bureaucrats deal with you in English? It’s a question of scales. In Valencia they learn both Castellano and Valenciano which is good. They maintain their own culture and identity while being able to communicate with the outside world and I’m sure Comunitat Valenciana functions very well. You, on the other hand, want them to change to suit your own specific needs which,in my opinion, is both disrespectful and wrong.
Equally Comunitat Valenciana is a bit more advanced than Cataluña in that they do teach Castellano or Pais Vasco in their teachings.