Remember, the EU countries would pass business back and forth without let or hindrance but the UK could not. Since the UK was, in August 2015, a net importer (albeit from both EU and non-EU), are you certain the game would be worth the candle?
If the UK is a net purchaser from Europe then even if we leave it will be in their interest to make buying/selling between the UK & Europe as easy as possible, or they're losing a large market.

Germany does not hate us and does not want to see us go.
Of course they don't. Apart from being a large market for their good, the UK is a net contributor to EU funds.