Fares out of Heathrow are expensive because the airport is successful. BA has played a large part of that success.
I don't know why you think Steven Byers is anti-BA. He seems to have been very even-handed with any allocations which have happend.
Why does T5 mean less competitors? BAA have said the opposite. BA is reducing the number of passengers it carries when T5 comes on-line, and other carriers are increasing capacity and flights.
Nick