“My own MP was a very strong Remainer, but his constituency voted to Leave.”
I keep on asking, but nobody answers. How do you know his constituency voted to Leave?
“But I have seen the votes counted in towns, cities and constituencies,…”
No you haven’t, Mikey. What you have seen are “estimates”. If you look at the results you will see they only provided down as far as “local areas”. For example, the results for Wales were split into 22 such areas. There are 40 Parliamentary constituencies in Wales and a good many more cities and towns. So it is not possible to determine how a particular constituency or town voted. Here are the only official results available:
http://www.electoralcommission.org.uk/find-information-by-subject/elections-and-referendums/past-elections-and-referendums/eu-referendum/electorate-and-count-information
“What is it that puts the EU referendum into a different category, dictating action in a black or white fashion based on a 4% difference between the two responses ?”
It’s this (taken from the then-governments scare pamphlet issued to all households prior to the referendum):
"This is your decision. The Government will implement what you decide."
Could not have been clearer. There were no provisos. Nothing said “provided the result is a two-thirds majority”. Nothing said “provided more than xx% of the electorate bother to vote”. Nothing said "provided enough MPs agree to your choice". Nothing else was said. That is why the referendum result is in a (totally) different category to a General Election result.
Comparison with the US Presidential election is specious. As has been explained, that vote depends on the “Electoral College”. The referendum does not. It was a simple binary choice with the highest number of votes prevailing (see above).