I'm an spanish citizen thereby granted to have free access to all national territory. If just catalan people is allowed to vote, then they are depriving me, and other spanish citizens, from the right to freely visit/live/work in catalonia.
All Spanish people have the right to decide about all the things in Spain, not just a bunch of people.
If some workers had followed the law maybe you would still work for 12 hours and a shitty salary (now that i think... this still aplies now)
Who deprives you from working, living and visiting Catalonia?
I understand this affects Spain as a whole, so after the vote there should be a proper discussion rather than direct secession action (IF that were the result). But this question is regional, the rest of Spain doesn't decide if they want to live in an independent Catalonia state, because they don't live in there.