The answer is very simple.

For the vast majority of passengers the balance of the fare between the YQ and fare components is not relevant.

BA will see a multi-million Pound revenue stream from revenue attributable to YQ on redemptions. It would take a Commercial Director of singular courage to abandon that tangible and measurable revenue stream for intangible and much harder to measure "loyalty benefits".

Furthermore, an individual with such courage would probably be unlikely to rise to the rank of Commercial Director at a company like BA because they would either be seen as too much of a risk, too busy running their own businesses or otherwise engaged trading futures contracts at a merchant bank for a million a year. And even if such an individual was in the post, they would still be unable to get such a proposal past the rest of the board!