Earlier quoted context omitted.
Good point - I agree, and I'm really disappointed it didn't play out like that. Instead the UK has had political stalemate for 3.5 years and even now it doesn't look like we're closer to 'a deal'.
I don't think a renegotiation after the referendum could possibly have achieved anything. Discourse about the EU in the UK is not based on facts. The EU would never have given compromises on freedom of movement, or the single market, and there wasn't anything else specific that people were asking for.
With a negotiating stance of "they just voted out, what can we give to avoid this?", I am sure some package that didn't compromise the aims of the EU too far, or cost billions, could have been worked out.
Now, whether a second referendum would have swung back to remain, now I'm clueless. :)