As much as I think Brexit was (and is) a disaster that was really just a reactionary vote against immigration (particularly POlish immigration), I think "Scexit" is a mistake and fail for the same reasons that there will be Ireland reunification.
Land borders. In Northern Ireland this creates a problem because you eitehr have to have a customs border between NI and the Republic of Ireland or between NI and Great Britain. The first can't really happen. The second is more natural but separates the Unionists (Protestants) from the UK but it's the only practical solution.
Combine this with the Republican (Catholics) population growing faster than the Unionists and Brexit has made reunification essentially inevitable.
So imagine how "Scexit" would work. A hard border between Scotland and England? It's almost as unworkable as a border between NI and Eire. This is really why Scexit has failed and that'll continue to be the case.
Not every border has to be a hard border. The Scottish border would not necessarily have to change at first because an independent Scotland would not be automatically part of the EU or even the Schengen area. If Scotland wants to join and the status of Great Britain is still not clear by then, then that's another border issue to resolve.
The situation with Northern Ireland is different because Ireland is part of the EU, and no one wants Northern Ireland mainly as a smuggling route between the EU and Great Britain. It has crossed my mind that some folks must have thought about smuggling/regulatory arbitrage as some sort of Brexit dividend for the UK as a whole, but so far this doesn't seem to be happening.
> The situation with Northern Ireland is different because Ireland is part of the EU
It's also significantly worse, as there's only around 25 scotland-england border crossings, whereas there are over 200 border crossings between NI and ROI (more than on the entire eastern border of the EU).
> The Scottish border would not necessarily have to change at first because an independent Scotland would not be automatically part of the EU or even the Schengen area
The rUK government is likely to be as bloody minded as the EU has been and acting in it's own perceived interest (which is not purely financial). It would be able to make things very difficult for an independent Scotland if it so wanted.
I'm not really sure I follow - the NI and Ireland example seems like a poor one because of the political history.
Why is a hard border unworkable in the Scottish case? I could definitely imagine this is true, e.g. if Scotland has to import much food or other goods. Or because Scotland depends on the pound. And maybe, in that way, it shares some parallels?
It's actually easier than in the NI-Ireland case. There are less border crossings to check between Scotland and England (due to geography), than there are between Ireland and NI (due to the fact that the border is entirely artificial).
Land borders. In Northern Ireland this creates a problem because you eitehr have to have a customs border between NI and the Republic of Ireland or between NI and Great Britain. The first can't really happen. The second is more natural but separates the Unionists (Protestants) from the UK but it's the only practical solution.
Combine this with the Republican (Catholics) population growing faster than the Unionists and Brexit has made reunification essentially inevitable.
So imagine how "Scexit" would work. A hard border between Scotland and England? It's almost as unworkable as a border between NI and Eire. This is really why Scexit has failed and that'll continue to be the case.