With friends like these why are we in the EU?

The UK is one of the rarest if things: a EU state which pays much more into the EU than it takes out. It is probably unique in applying all the petty laws the EU decree no matter how damaging it is to Britain. We've handed over our lucrative fishing grounds to the EU fleets at the cost of tens of thousands of British jobs, tens of billions of lost revenue, and to the devastation of our fish stocks. 

So why is it that the other EU states seem to hate us?

Just because our PM decided to exercise his right under the EU law to veto a agreement which would have destroyed a vital British industry we have been under sustained attack by MEPs and the French state. 

We are now beyond the pale. We must be made to pay for not towing their line. Germany demands that we pay countless billions more into the bottomless bucket that is the EU as a punishment for daring to not do what the Germans tell us to do. 

My question is this: why are we a member of a club which costs us much needed billions, which we pay extra tens of billions, up to fifty billion so far, in propping up other members, a club which destroys business and costs us jobs if they attack us so?

The EU is an important market but they need us much more than we need them. If we leave we would still have the same access to the EU, as do fifty odd countries from around the world. 

So why stay if instead of friendship and gratitude for our money we get hate and are made the fall guy for the mistakes of other governments?