Not sure I agree, given the frequent flyer program is the one part of the business that makes money, yes the airlines want to maximise their profit. But they don’t want to kill it!
FF programs have always been a pretty cough deal for your average Joe Blow (that’s how they make their money), but there always have been ways for the smarter aficionados to leverage benefit.
It’s a fine line but if FF programs become useless to everyone and everyone stops using them they lose all that, IMO they have to have some appeal to some users or they are killing a golden goose.