1. It appealed to misguided "British" values
Millions of Brits were attracted to the idea of homogenous England of old. Xenophobia is on the increase and Brexit did a great job of normalizing racism across Britain.
"There's a little Hitler in all of us", wrote Andrew Sarris in 2002, "if we are not held back by any moral or social restraints."
Brexit made the normally pathological act of denouncing ethnicities and religions a normative one. Much of the campaign rested upon the idea of an imagined Britain of the final years of WWII when Churchill was a hero and Ghandi a terrorist.
2. They weren't wrong about the EU
The EU is a very clunky beast which was caused a huge amount of economic problems for countries such as Greece, Portugal, Spain, and Ireland.
It's a system of open markets in which competition is eviscerated in a shared currency. Britain has never taken on the Euro, and therefore managed a position of reasonable strength - but the Brexit mob isn't wrong about the unwieldly and regulated organ.
3. It was a revolt against prescriptive elitism
Just like Donald Trump's populist movement across the United States, Brexit was a movement with a place for the everyman to stick it to the banks, the politicians, and the corporations who've been prescribing ideology to the masses.
Like our own Flag Referendum, it was an opportunity for the country to collectively say "get stuffed" to the Government.
4. Leaving may curb immigration to Britain
There is an argument in England that Poles and Romanians have caused unemployment. For every able British person to do a job, there are 50 immigrants who will do it cheaper.
This is an emotional argument which feeds into xenophobia but is a massive cornerstone of Brexit campaigning, especially from Nigel Farage.
5. Scaremongering from the British press
A number of very well-read British dailies have made no secret of their support for Brexit, meaning skewered facts and biased reporting may be diluting the facts about Britain leaving the EU.
A recent article from the Daily Mail gave "20 reasons why you should choose to leave."
6. It's made a mockery of David Cameron
The British Prime Minister reluctantly agreed to hold referendum for leaving the EU to quell the unrest coming from Euroskeptics within his party.
It has spectacularly backfired and heralded the resurgence of Nigel Farage. David Cameron is now grappling with a country in revolt, and Boris Johnson hasn't done him any favours by joining the bandwagon.