I suppose the Spanish government didn't do a good enough job of convincing the Catalonian people that they are part of Spain.

The majority of catalans don't want independence.

The political parties promoting independence represent less citizens than the political parties that want Catalonia to be part of Spain.

So really, the Spanish government should just have let the referendum go ahead peacefully, and thereby have had that fact publicly demonstrated.

Self-determination for some, miniature Spanish flags for others!