It's an interesting phenomenon - it genuinely hadn't occurred to me that there is a proportion of society who believe they have the right to irreversibly change the fundamental structure of Governance in the UK and Commonwealth, based on nothing more that current social values. As a pp said, if there had been a revolution, constitution etc then that would have formed part of our history.
It never ceases to amaze me that those most in favour of our monarchy appear to know least about our history.
We did have a revolution, it fundamentally changed the role of monarchy, the constitution and leadership of the country.
To answer another point raised, in the longer term it was the opposite of destabilising as it's widely believed that a shift from absolute to constitutional monarchy was part of what protected UK from the extremities of the French Revolution.
- Go educate yourselves.
Change as a response to 'current social values' is baked into our history.