Not sure that's an argument that shines good light on brexit voters.
Perhaps that they're wonderfully trusting people who believe whatever politicians that Gary down the pub thinks are the best ?
In the broader scheme of things you could also see this in the response of Brexiteers who were stunned that, as non members they now weren't able to travel freely across borders.
Voters aren't very bright because they're people, you've met people. I used to think that FPTP was a good idea because it's so simple that "The candidate who had more votes won" means the idiots won't be confused by the outcome. We saw that they're confused anyway, so, fine, since apparently simplicity wasn't achievable we should use a more complicated voting system with better outcomes.