Does anyone know a rough figure of how many LHR slots BA actually owns? Due to the size of their operation out of there I bet it is a right monopoly. And I guess it opens up the question; why is Heathrow such a popular base for airlines? These days more and more airports are looking desirable with improved transport links and so on, the only real difference I can see compared to the likes of Gatwick / Luton / Stansted is that it is on the tube.
BA has about about 43% of slots at LHR which is significantly less than what AF, LH and KLM have at their respective hubs.
BD's share of slots at LHR has now fallen to about 8% after LH group has extracted slots so even if BA acquired BD without divesting slots its share would still be barely above 50%.
BA acquiring BD would enable new routes to be launched with the slots (China in particular) which will make LHR more competitive against other hubs so I don't see what is detrimental to the consumer interest.
As for LHR a lot of US inbounds are located in the Reading/Thames Valley area making LHR very convenient. It's network for business travellers also perpetuates its popularity and any other London airport would struggle to ever replicate this.