Hyacinth, I understand the points you have made, and honestly understand & agree with what you are saying.
However, put some of them into the wider scale.
The majority of people in NI want the UK to remain in the EU.
The majority of people in the UK as a whole want to leave the EU.
The Troubles featured a number of people not doing what the majority wanted and not being too concerned by this lack of a democratic mandate.
I know.
A violent and vocal minority tried to ride roughshod over the feelings & wishes of the majority, which is never right & never has a good outcome.
Historically, this is what the English did repeatedly all over the world, including Ireland, Scotland & Wales, hence the deep rooted suspicion and hatred of England in many places across the world.
'What the majority want' is not a universally accepted concept in NI anyway, because various groups there will define said majority differently. Everyone in NI is a minority in one sense and a majority in another. It is a different world from rest of UK politics in this respect. There is no hope of understanding NI politics without understanding this.
The UK as a whole is the same.
There is no homogeneous mass or hive mind - we are a country of individuals, and as such we voted individually in the referendum.
The majority of individuals for their own individual reasons and motivations voted to leave the EU.
Majority wins in a democracy, and one would hope that this would involve concessions to the sizeable minority who voted the other way.
A vocal & potentially violent minority within a minority within NI, which in itself is a minority shareholder in the UK as a whole, absolutely cannot and should not be allowed to dictate against the will of the majority of individuals within the UK as a whole.
The fact that 'what the majority want is not a universally accepted concept in NI', should not take precedence over the fact that in the democratically run UK it is precisely what matters. As it should be.