What, you mean those votes we always re-run, some even annually? Nice argument.
Next you'll be pretending the 2016 vote was the first vote on this subject so you dont have to accept that it was already the second vote and can have a stance that we shouldnt have a second third. Oh wait....
I'm delighted you mentioned the 1975 referendum. Thank you.
43 years ago people in the UK were asked to decide if they wanted to continue being part of the Common Market, a trading group of nine European countries.
Since then there have been a series of significant European treaties signed;
TREVI
The Single European Act
Greenland
Schengen
Maastricht
Amsterdam
Nice
Lisbon
The Protocol on European Parliament seats
The TFEU ESM Amendment
The Irish Protocol on the Lisbon Treaty
Plus six, (yes six!), different Treaties of Accession
All these treaties have completely changed the direction and purposes of the ECSC/EEC/EC/EU.
The UK joined the EC, a collective name for the European Coal and Steel Community, the European Economic Community and the European Atomic Energy Community.
The referendum in 1975 was about stronger trading between nine countries. There was nothing in that about the free movement of people in Europe, a single European currency, expanding the group from 9 to 28 nations, nor the EU's future plans to remove further sovereign powers, create a single European border force (crushed just recently), to create a single European army, and so on.
Of course, being a huge Europhile you're completely across all of this and just how much and how often the ECSC/EEC/EC/EU. has changed and rearranged things in its unending power grab.
To compare the referendums of 1975 and 2016 is spectacularly naive.
There are 43 years, 17 treaties, 19 countries, three names, and a single currency's worth of changes to be considered.
But weirdly you think the 1975 and 2016 referendums are similar or proportional. Nice argument.