If we are playing soccer and you want to join but are refused repeatedly because you want to play handball (Charles de Gaulle vetoed the UK entry twice), then you somehow sneak into the soccer game and then decide to handle the ball, then, to quote the Simpsons: "that's a paddlin'".

I'm exaggerating for effect, but the EU has a clear set of rules. It's not fanaticism, it's called "working together". The UK, not the EU, decided to stop following the rules. It makes no sense for the EU to bend the rules.