In my experience Scot Nats get very touchy whenever a non-Scot gives any sort of a view, unless it agrees with them. Saying that a person has a right to an opinion, but noting the opinion is worthless is pretty much the same as saying they have no right to an opinion.
It is one step away from telling them to shut their gob because they don't understand the issues.
My memory of my time in Scotland is the endless comparing and contrasting, pretty much always done to show how much better the Scots were at everything. E.g.:
Scottish education good; English education bad.
Scots - egalitarian; English - class bound.
Scots - friendly; English - stuck up snobs.
Scots law - rational; English law - constipated.
Scots - welcoming to immigrants: English - racists.
Scots - progressive: English - C***s,
Scots pro European and cosmopolitan: English anti-European and insular.
Scots - loved by all over the world: English - hated all over the world.
Scots - invented everything: English - nicked everything
Scots - cultured: English - knuckledragging troglodytes but at the same time..
Scots - frank and robust: English - effete.
Scots - good humoured: English - touchy.
Black pudding and porridge good: bacon bad.
Scots - stick up for the underdog: English - fart on the underdog.
Scots - tell the truth: English - tell polite lies.
In the past, there was also:
Scots sent missionaries to the Empire: the English sent soldiers
Scots: rational Calvinists - English: crypto-Catholics.
And so on.
Now my memory of Scotland is that a great many Scots didn't take this sort of nonsense seriously at all. But a good many did, and if you really have that sort of a conceit about your ethnic culture, it is easy to believe anyone who says you're not getting a fair deal, because the English (or "Westminster" as they are cryptically called now) are such a bunch of subhumans.
It also enables a sort of doublethink, as evidenced by nationalists complaining that Unionists are being inflammatory, while simultaneously bandying about terms like "bullies", "thieves" and "scaremongers".