The A318 was hardly a misfit, it's a smaller version of the A319/A320 of which BA have a substantial fleet. The costs of using the service were high and I understand it did well for a period, novelty value initially. You say "killing the competition" is a BA tbing, well I am amazed that news of a certain "Ryanair" never made it to the south side. They took out KLM uk and mutilated what remained of Buzz. When easyJet tried to fly LGW-Ireland the response from Michael O'Leary was vengeful and focussed like a laser beam, just as they had attacked Go when they entered GLA/EDI-DUB. It's what succesful airlines do, they defend their home markets. Ryanair defended STN/DUB, BA defended LON-NYC.
Your anger that BA launched LCY-JFK is misplaced, LCY is a core BA market, it has the highest % of Gold Card holders per flight on the whole network, proportionally more than LHR. And given New York and London are both key financial centres, a LCY-JFK operation was tempting in it's own right, regardless of anything going on at Stansted. And stop calling them "bean counters", it just shows you have no clue about how a business actually works.