All the central govt. had to do was declare ahead of time the results had no legal standing. Instead they acted in a violent, senseless manner that proved they weren't a modern democracy.
The people in Catalonia who were on the fence then shifted into the exit camp.
And asking a "King" for permission to exercise self determination -- when they would have gotten an instant "NO" -- laughable.
Their biggest issue is no-one is going to recognise them. The entire process was so mishandled from both side its legitimacy is never going to be accepted.