The EU and the ECM (what was voted for back in 1975) are two different beasts.
Maastricht and Lisbon treaty would of been key changes in that transition that many countries had votes (and also revotes) upon. The UK, did not alas and it is pretty obvious that it should of.
Ironically, the children of 1975 era had no say in their future until 2016 and you can see how they voted. Also those that who in 1975 voted to join the ECM, turned out to be twice as likely to vote to leave the EU in 2016.
But the whole aspect of thresholds is one that does need some thought and equally turnout. Maybe voting should be compulsory? Maybe threshold standards need to be defined.
After all, does the EU really want to have members who are not that commited to the goals?
Democracy is a fickle matter depending upon how you measure it.
To make matters more complicated, the primary reason the UK isn't part of the Euro is because Britain crashed out of the pan-European exchange rate controls in 1992; if it wasn't for the "Black Wednesday" crisis, the pound sterling may have been abolished, again without popular referendum.
Both predicting and contributing to this crisis was George Soros, who shorted the pound sterling and profited immensely from it. This is one of many reasons he is a controversial figure in some circles.
ERM and the Euro, whilst somewhat entwined are not mutually inclusive. The reason the UK never took on the Euro, was many fold and nothing to do with Mr Soros and the great EMF gamification for printing money.
If they did a referendum upon the Pound and the Euro in the UK, the result would be much clearer and conclusive than any membership referendum. Heck, even Scotland if it leaves the UK, wants to keep the Pound.
One aspect the UK has impacted the Euro has been in blocking (as a members vote) many initiatives to control the financial markets and with that, been instrumental in curtailing the controls needed for a large encompassing currency.
But I totally disagree that the UK's primary reason for adopting the Euro was due to the ERM shenanigans. https://www.economicshelp.org/blog/215/uncategorized/why-uk-... covers some reasons. But to say it is complicated is part and parcel of any currency control.
Remember, the UK's key income area's are Financial and Services, two area's in which the EU has been stymied to take control of, mostly due to it not being in the UK's main interest. Heck, even opening up services has been a backfoot EU initiative with members still not opening up those markets. But that is another matter, equally complicated and hard to summarize in a few sentences.
