Many nations are in major turmoil politically and financially. Britain is one of those nations. The citizens that vote and allow for their political leaders to make choices that hurt their world status as well as their economic value is all on them. Citizens of any nation can stand up and let it be know what they want, but many just do nothing.
Yes, if Britain is broken, I believe that they have themselves to blame, because they have seen how the European Union has gone, and they have had many opportunities to do things differently. Britain could have made changes to save their economy and stabilize their finances, but they have not done so, while their social state has exploded.
Britain cannot address it's issues, without first acknowledging where they come from, and taking a good hard look at itself. Blaming outside influences is always the mark of someone unsure of themselves frankly. Weak governments blame foreign agitators for internal problems. Then again, it must be hard losing an empire, a hundred years ago, they used to be somebody.
I personally think that Britain is broken but they have themselves to blame due to what has happened in the past. I personally think that Britain was broken because of what caused it and how it affected so many people. I personally think that Britain was Britain but they have themselves to blamed due to Britain being broken.
If Britain in broken, it is obvious that they only have themselves to blame. I believe Britain has made good global choices as far as letting go of its colonies, but if there is something wrong within their government they can't really blame anyone but themselves. They haven't really dealt with opposition or had to fight battles at home.