That is the entire point of the TATL JV they have with BA; they share the revenue. “Pushing” to BA means AA still sees a check. It means if AA thinks they have a better use for a plane than JFK-ZRH they can send the traffic to BA and make money flying elsewhere. You may not like it, you may think the CEO is an idiot, AA’s estimation of what the best use of their planes is may be wrong, but there it is.