This question cannot, of course, be given a definitive and objective answer. Such questions are really matters of interpretation, not of objective fact because we cannot "scientifically" isolate causes of events (or non-events, in this case) and experiment with them to prove that they are the actual causes. That said, I would argue that the reason for this was that Great Britain was a relatively liberal society with much more of a chance for political participation on the part of the working class and much less repression than happened in places such as pre-Soviet Russia.
One cause of revolutions is pressure that builds up because it has no outlet. In Great Britain, this did not happen nearly as much as it did in Russia. In Great Britain, the grievances of workers were at least aired and even got some amount of redress. An example of this would be the Reform Bill of 1832, which gave workers some (albeit limited) ability to be represented in Parliament.
Since Great Britain's system allowed for some amount of change (as opposed to Russia's stringent adherence to the status quo) a revolution was less likely in Great Britain.