I think you may have missed my point.
You are correct in saying the lounge at LCY is adequate – but only for the JFK flight with its short check-in time concept. It is minimal (as your photo shows) and just consists of a few seats around the dedicated gate but it is sufficient for the short time you spend there (it only opens for a short time before departure). It is not designed to ease the pain of a 4 or 5 hour connection.
It is not a lounge that would be of use to any other traveller as it is purpose built for the short-check-in-quick-departure concept of BA001.
LCY is a great little airport with quick check-in and ultra rapid security which negates the need for T5 quality lounges.
The LCY-JFK A318 service is one of the very few innovations from BA that I have enjoyed over the past couple of years and I hope its success continues.