Yes, it's complicated. From what I gather, immigration -- a desire for lack thereof -- inspired many British voters. I.e., they're not into the freedom to cross borders; at least not theirs, at least from the other side. But, again, they are into the freedom to make their own decisions (as we all should be!), be it regarding borders or whatever.
The problem with endeavors the likes of Brexit is that they are inevitably, and aggressively, propagandized. Folks are fed what a particular political group -- promoting their own political agenda -- would have them believe. And if it happens to jibe with enough folks' personal biases, then a crowd forms, and, alas, crowd mentality takes over.
From one of the most instructive books on human nature you'll ever read, the 1895 classic, The Crowd: A Study of the Popular Mind, Gustove Le Bon wrote on the contagion that has individuals taking positions on behalf of the crowd they find themselves in, often to their own personal detriment:
In a crowd every sentiment and act is contagious, and contagious to such a degree that an individual readily sacrifices his personal interest to the collective interest. This is an aptitude very contrary to his nature, and of which a man is scarcely capable, except when he makes part of a crowd.This morning's news:
Banks Are Said to Begin Brexit Moves Despite Transition Call(Bloomberg) -- Big investment banks with their European headquarters in London are forging ahead with plans to create new trading hubs elsewhere in the region in preparation for Brexit despite the U.K.’s pledge to secure a two-year transition period after March 2019, according to people with knowledge of the situation. The global firms, which employ thousands of people in Britain........Oh, and yes, there are investment implications here...