(Un) fortunately (depending on your personal prejudices) It is the preferences of transit pax (especially Americans) that need to be taken into account as if transitting the UK becomes too difficult ,then they wont fly via the UK. I´m sure France, Germany and Netherlands plcs´ are rubbing their hands in glee at the UK´s typical indecision.
Too true - and with the exception for Germany, they all fly into the capital city. Europeans however, do not give a toss whether the hub if JFK, ORD, DFW or wherever, they use the route that suits their requirements. Perhaps more US carriers need to use other airports and use their alliances (whilst they still exist!)