Nobody who voted to leave should have expected the UK to receive (favourable) special treatment. If they did they were foolish.
On the other hand I suspect many looked at Switzerland and Norway and decided "yes, that would be quite acceptable".
I would be prepared to bet a lot of money that had the choice been honest, i.e. between "Remain" and "Hard Brexit, with no SM/CU and difficulties with emigration" Remain would have got more votes than Leave, and probably by a substantial margin.
There were I suspect a lot of "soft Brexiters" who had reservations about the EU but wished to retain FoM/SM/CU. And still others who didn't care either way, but just wanted to spite David Cameron.
Hard Brexit was implemented for political gain, and political gain only, because the Tories knew that they could win elections from the votes of a coalition of traditional Tory voters and small-c conservatives whom hard Brexit appealed to.
So should anyone expressing support for Brexit in 1983, or indeed any time after that, been told by EU supporters "I can't believe we're still having these arguments..." - because the 1975 referendum had settled it once and for all and arguing about something eight years later was pointless?
I suspect most would answer No.
The inherent bias I find in a lot of Brexit supporters is that it was quite acceptable for them to spend years complaining about the EU, but as soon as those of us who want to be in the EU start complaining about Brexit, we're told "the decision has been made, accept it...."
It's as if the 2016 referendum is somehow more binding than the 1975 one. In reality, 2016 is just as much a random year in history as 1975 is. What people believed in 2016 is not necessarily what they believe now.
It's a popular example of a loaded question (jokingly asked by some US TV presenter, I think). You asked two questions to which, if anybody answered "yes" to both (which many might), would indicate they must support EU membership.
Ah ok, thanks, sorry. I was completely confused by it.