I wouldn't be surprised if there weren't any more Catalan elections or the independence parties were banned from standing in them.

Mmmm, that would degenerate rapidly into civil disobedience. It is hard to see how the central Spanish government can change the opinions of a big part of Catalan society by playing hard ball. I would say that the harder they go, the most people they antagonize.

And therein lies the problem: 15 years ago the amount of pro-independence was relatively low, but the Central government has refused to take the demands of the Catalan government seriously.

The current political class ruling in Spain is completely overwhelmed on how to deal with a changing society, and the structure of the Spanish State is inflexible, to the point of having to argue that in order for a region to push for the changes they feel they are entitled to, first they need to reform the Constitution, something that is impossible to achieve since the reforms they want to implement are blocked by exactly the same people that would block a reform of the Constitution. Go figure.

That's a coup of the Spanish State, isn't it?

True, and this already happened in the last elections to the Catalan Parliament (Generalitat). But it's sad to fake referendums by hijacking elections, which exist for completely different reasons. This just mixes and confounds lots of different issues, and makes parliamentary elections meaningless.

The question of independence is complex enough that warrants a dedicated vote.