For an EU exit to be an agreeable choice, well at the risk of being drawn into an argument based on inappropriately simplified premisses, but here goes...
To exit the EU I think a fundamental member nation like the UK would need to observe, without cynicism, that the EU was somehow now incompatible with the UK's long-term socio-economic plans.
The UK would then need to make a thorough exit plan that demonstrably showed, again without cynicism, how the UK and its people would prosper and continue to support its allies and uphold it's principles and commitments.
This plan would then need to be proposed to the people in clear terms, without bias, without a marketing budget in an engaged bipartisan, honest manner.
In this day and age it really is not hard to see what is wrong with politics. It's so easy to imagine a 'better' way of doing almost anything. There is far too much polarity, one-upmanship, ego, self serving, and down-right 'fuck you' to the opposition. Trump and others literally fuck over the previous incumbent's changes just for the status and message it sends. Almost nothing is done for 'the people', everything is done for show and status. There simply is no substance any more.