Some people will vote out just because they hate/mistrust Cameron; others because of the migrant/illegal immigrant issue, and desperate scramble for jobs, houses, and school places... The fear of leaving isn't very strong, because nobody can really see much benefit from staying in. It seems that life would be a lot simpler being out. No need to worry about all the catastrophes afflicting countries across the water.
The EU seems to have failed to bribe enough of the public to keep them hanging in for the socialist economic disaster they're desperately trying pull together. They've also made it far too easy for their enemies. I mean the idiocy of letting all those people through, and the now frequent terrorist attacks, and corruption issues and yooman rites stories... ultimately not many people feel they have got much in the way of economic vested interests there. The few that have are pensioners renting out their gaffs to immigrants, or a special affluent urban lefty elite.
There's nothing in it for us.