I find this view almost endearingly naive. What, on their own, would one person or individual family unit be expected to do to make a whole country 'better?'
We receive a vote approximately once every five years. Some countries don't even accord that particular privilege. Sometimes we can protest, making the strength of public feeling absolutely clear. To what end? There was still a war in Iraq, no party having provided any credible opposition, and like idiots we immediately endorsed Blair's position by voting Labour in again at the next general election.
In a democracy the majority vote counts so if our compatriots happen to do mad, unfathomable things like vote in a party who line the coffers of the rich whilst driving public services through the floor, or even worse, appeasing their backbenchers with an ill-informed and disastrous Brexit referendum which went haywire when the country unfathomably didn't deliver the result they expected - then again, what is one individual expected to do?
There was a whole thread a few weeks ago posted on by British people in despair at the state of the country, and who were seriously looking into emigrating. Educated, smart, professional people: precisely the kind of people this country cannot afford to lose. And whilst there may be no such place as Utopia, there are opportunities to make good elsewhere if we wish. I wouldn't want these closed off to me (Brexit's made a great job of that in Europe; if you voted for it thanks for nothing on behalf of me and my DC), and equally don't see why they should be closed off for immigration in the other direction. My decision is about what's best for me and my family. If the UK is going to do stupid things like deliver a 'YES' Brexit vote, I don't consider it my personal responsibility to make that better.
Respect and admiration don't really come into it. Sometimes necessity, or the chance of better opportunities elsewhere, do.