Again, your entire point is around them not having succeeded in overthrowing a massive, complex, centuries old, highly resilient power structure which amongst other things indoctrinates them from an early age into compliance and even pride in it.
Things over there are massivelly rigged exactly to stop such a change, an many levels, from the First Past The Post voting system and a Press incredibly consolidated and either in the hands of either billionaires or controlled by the upper class boards, to the whole Public School -> Oxbridge -> Top Level Corporate/Legal/Public Service Position pathway that that makes sure the scions of the elites always end up in control of the rest.
Further, in many ways that structure has been cracking due to internal pressure, though as shown the last time it was really under pressure (following WWII and the return of large numbers of working class people with military trainin) it showed massive flexibility which is how Brits got the NHS, Social Security and even a Gilded Age in the Arts (from all the working class kids that flooded into Music and Theatre) during the 60s and 70s, though all those gains have been slowly been undone, especially since Thatcher got into power.
So you're basically saying that when peasants don't assault the fortress they're uncivilized a logic which ultimately (considering that there is always room for improvement) boils down to "Only Violent Revolution is Civilization"