FTA The Catalan government said that of the 43% of potential voters who took part in the referendum, 90% were in favour of independence. In a referendum where people who wanted to vote "no" didn't show up, because of fears of violence. This just isn't a reflection of the will of the population.
Not true. People came to the polls wearing Spanish flags. No violence. The Catalan process has thankfully been extremely peaceful. People did not vote in the referendum because it was not officially recognized as such. Because the Spanish government refused to agree on the terms. The referendum was a sad exercise of democracy, in which the voice of lots of Catalans was not heard. But it was the only one that could be…
It's more like "90% of the people who thought the referendum was legitimate are in favor of independence". There's obviously a big selection bias.
As for the question of whether the referendum was legitimate or not, the problem in my opinion is how can you consider a referendum democratic if only a tiny portion of the country's population gets to take the decision? Catalunia becoming independent would have consequences throughout the country, shouldn't everybody get to vote?
And if not, where do you draw the line? Paris and its region generate about 1/6th of the total GDP of France, what if Parisians decided to declare independence? What about the Lega Nord in Italy? And let's not even talk about the historical economic divide between eastern/western Germany or the variations of GDP between states in the USA.
What if all the rich people in Japan decided to all move to an inhabited island and declare independence with 100% of the vote? Would that be legitimate?