So basically any time a group of politicians decide they don't like the laws then they don't have to follow them and can do whatever they want? Big Trump supporter huh?

And there is an entire legal process for which those politicians could have had a legal referendum. They just decided that was too hard.

It is a complicated issue, because forming a functioning society is a complicated process. And Catalunya has entered into agreements from which they can't just act like little Timmy on the playground and say it didn't count because it was reverse day when he said it.

And again. I don't have strong feelings about the amnesty other than the external problems it could cause like an ultra right government coming into power next election. I don't even have major feelings about whether they should be allowed to leave. I do think it would be disastrous for them. They would essentially become a landlocked country, outside of the EU, lose freedom of movement to anywhere but Andorra probably, just holding the illegal referendum caused them to lose so much business and for what purpose?

This isn't the same as the issues in Basque country that predated the EU. It isn't Ireland. This is much closer to Brexit where a minority of politicians are pushing an ideology of Us vs Them. And I'm aware that there are legitimate complaints that Catalunya has. But there are much easier and more practical ways of trying to fix those complaints.

What's happening here is more similar to Milton county Georgia begging to be annexed by Fulton county (Atlanta) when they were broke, but now that things are good they want to leave and no longer be part of a system that has certainly benefitted them in many ways.

You are being an ideologue. You should give pragmatism a try.