I'd bet those J class seats on BA were cheaper than CX. Would you really pay more to be on the A380? I don't think so.
So who is it with "no clue" - BA for operating the no cargo carrying super jumbo and selling cheap seats or CX charging more and carrying 25T cargo in the 777 belly under your feet?
Do the math... It's not that hard to figure out that running an airline is more complicated than choosing your favorite jumbo jet.