Yes there are some very valid points in that post mgspain. However it misses the point by a wide margin.
If modern Spain is a grown democracy it should have the confidence to rule all their provinces with and by the consent of the people. That is the nature of democracy. The people rule their country not governments who can only effectively administer power by that consent. The alternative is anarchy.
A referendum is simply asking the people who actually rule in that democracy who and how they want to govern them. I realise that the old parliament argument is the people ruling by proxy but we all know that is a smoke screen for maintaining total power over a diverse and culturally fractured nation state.
An independent Catalonia will not go away. If the people feel disenfranchised they resort to armed struggle sooner or later.