Originally Posted by
FRatSTN
Take the Air India routes besides Delhi and Mumbai for example, or someone like Biman Bangladesh, who are very point-to-point, VFR market focussed. They can easily serve that demand from LGW or STN. LHR offers those routes/passengers nothing other than the fact that it's Heathrow.
Heathrow has obvious advantages over LGW/STN for the extensive Asian community in West London.