I don’t discount much of what you say except that’s like saying the Catholic Church or the Evangelical world or the Republican Party or America or UK itself doesn’t have some inherently systemic issues that are compromising their institutions from within — even without any external disturbances. The British monarchy has stood the test of time despite (our 1776) revolution and the downfall of its neighboring monarchies in Europe. Obviously it’s done a lot right.
But It is not beyond reproach. And it does need to take a deep look in the mirror every now and then.
We certainly do agree on that, especially for egregious injustices, or even legitimate modernization, like the recent law that would have allowed Williams' firstborn to be crowned even if it had been a girl, whereas before, she would have been passed over for a younger brother.
But as a test case, this particular one with M&H is full of holes.