Sad, isn't it, how democracy allows an electorate to change their minds?
But the whole basis of the referendum was a on shot deal with immediate implementation. That hasn't happened. In a democracy you get to change your mind every 5 years - vote for the same government, or a different one; but you don't get to change the elected government before they take power. Voters wishes are enacted first - then after a reasonable time span, during which what they voted for is implemented and assessed, they get asked to express those wishes again.
Nobody is saying there can't be referenda on rejoining the rEU after we have left, but if you don't implement the result then that is not democracy.