If it's not language/culture, then what else is it?
Language and culture is not the same thing. Language is apart of culture. I would say it is based on political reasons but then that can be reduced to cultural reasons. You have yet to find an example of language being primarily the reason of separation. Do come back to me with evidence.
It's up to you to provide an alternative source of independence desire and then I'll see if it works or not.
I don't understand this. Are you pushing the burden to me when you are unable to fulfil your side of the burden? If it isn't that then this comment is a non-sequitur for your claim language being the reason for separation or the start of it.
You cited that Catalans wanted to vote, however, Spain is a democracy, otherwise they would not be allowed to be in the EU.
The Catalans wanted independence which was being stopped by Spain. If democracy was actually the rule there the government in charge should not be allowed to stop a vote taking place.
Despite the Spanish court also banning the non-binding vote, the Catalan self-determination referendum went ahead on 9 November 2014.
They weren't able to use the democracy to vote for something they wanted.
Catalans can in other words, already vote.
Not true.