One counter-argument would be that a democracy, in the modern sense, is an arrangement where people aren't interrogated on their reasons for voting. Everybody votes, and the collective vote delivers the correct answer. Whatever it is, it's the wisdom of the people. The referendum was approved, and its terms set, by our parliamentary representatives. There were valid reasons for voting Leave, not all of them capturable in economic indicators, and I have no time for the "Leave voters are racists!" nonsense.
What strikes me, though, is that the referendum, on the scale of politics, is ancient history. "Brexit means Brexit" is one of the most ambiguous - at least, flexible - statements of modern times. A lot of politics has happened since then. We may end up with a settlement that looks more like Remain than Leave; there may be a debate one day as to whether we ever left at all. Isn't it naive, to think that the result matters, now that the politicians have taken over? What purpose does this argument serve?