BA probably wants its "competitors" to also accept not ratcheting up by too much the "costly" "competition" for premium cabin customers.

Dragging your heels on upgrades is a way to try to signal to the "competition" that investing in product upgrades to become more profitable isn't as necessary as it used to be, so let's have a joint approach of sorts to not continue the upgrade way and instead boost our profit margins at the expense of consumers.

Also, BA's got so much market power by its domination of LHR that it can hold back on major product investments. BA is sub-par in so many ways, and LHR is a mess in so many ways, and yet BA has been ok with being sub-par in so many ways even as the LHR transit experience is as bad as it is.