The demographic of Scotland really hasn't changed very significantly since 2014. Serious change of that nature takes decades.
You don't want people from other parts of the UK and Europe living in Scotland to have a vote on constitutional change?
How ironically undemocratic of you - bigoted as well!
You seem to be under the impression that there is a right to secession in international law and politics too. There, in fact, is no such right and only two countries give citizens that right.
But it's both democratic and legal for every state to say no to secessionist demands.
Secession is not a democratic right
"Currently, among the constitutional laws of the world, only two states carry the right of secession in their constitution: Ethiopia, and the Federation of Saint Kitts and Nevis."
“In the Federal Republic of Germany, which is a nation-state based on the constituent power of the German people, states are not ‘masters of the constitution’.
Therefore there is no room under the constitution for individual states to attempt to secede. This violates the constitutional order.”
- Ruling from the Constitutional Court of the Federal Republic of Germany.
"The Constitution is based on the indissoluble unity of the Spanish Nation, the common and indivisible homeland of all Spaniards; it recognizes and guarantees the right to self-government of the nationalities and regions of which it is composed and the solidarity among them all."
- Section Two of the Spanish Constitution
"France shall be an indivisible, secular, democratic and social Republic."
- Article One of the French Constitution
"The Republic, one and indivisible, recognizes and promotes local autonomies; implements in those services which depend on the State the fullest measure of administrative decentralization; accords the principles and methods of its legislation to the requirements of autonomy and decentralization."
- Article Five of the Italian Constitution
"It is clear that international law does not specifically grant component parts of sovereign states the legal right to secede unilaterally from their "parent" state....
The various international documents that support the existence of a people's right to self-determination also contain parallel statements supportive of the conclusion that the exercise of such a right must be sufficiently limited to prevent threats to an existing state's territorial integrity or the stability of relations between sovereign states...
A state whose government represents the whole of the people or peoples resident within its territory, on a basis of equality and without discrimination, and respects the principles of self-determination in its own internal arrangements, is entitled to the protection under international law of its territorial integrity."
- Canadian Supreme Court ruling on the issue of secession
"I pledge allegiance to the Flag of the United States of America, and to the Republic for which it stands, one Nation under God, indivisible, with liberty and justice for all."
- United States of America Pledge Of Allegiance
"The answer is clear. If there was any constitutional issue resolved by the Civil War, it is that there is no right to secede. (Hence, in the Pledge of Allegiance, ‘one Nation, indivisible.’)”
- Supreme Court Justice Antonin Scalia in 2006
“Article 52 of the Constitution is a unitarian structure, indivisible, indecomposable."
Dean of the Brazilian Supreme Court, Judge Celso de Mello
"WHEREAS the people of New South Wales, Victoria, South Australia, Queensland, and Tasmania, humbly relying on the blessing of Almighty God, have agreed to unite in one indissoluble Federal Commonwealth...."
- Preamble to the Constitution of the Commonwealth of Australia