Poppycock !! LHR is one of the most competetive markets in the world. LHR is not just BA and VS; have you looked at a departures board recently?
So when BA convert most of the BMI slots into long haul routes (and not forgetting the tie-up with AA), and most who have tried American carriers would only do so again on 'pain of death' then not such 'poppycock' i would suggest?
Either way, competition and good competition at that is essential.