Perhaps you can give an opinion as to why in the recent past both BA and Cityjet nominated SEN as number one weather diversion, seeing as "Southend is remote"
It's the closest airfield to the STARS from the East where much of the traffic comes from and is uncongested, allowing a "splash and dash" for when LCY reopens. Failing that it allows passengers to be offloaded and aircraft to be winging their way elsewhere quickly without getting too deep into the congestion of the London TMA. It's absolutely nothing to do with available market and profitability.
Indeed you can read off the registrations quite easily off traffic going into LCY from SEN. It's on the coast beyond the M25, you can't define it as any more remote if you want to call it a "London" airport as if it were any more peripheral, the locals would need gills and webbed feet.