The BA179 LHR-JFK/BA182 JFK-LHR was also cancelled due lack of crew. Regardless of booked loads we are a scheduled airline and should run services based on said schedule. Just because the BA215 load was poor doesn't mean the inbound load was the same. One last point, don't forget the freight, regularly we load 10-15 Tonnes of freight on these flights (which happens to pay quite well).