However, let me use one example to illustrate why I think it's a self harming policy.
BA's revenue management policy is generally to charge a lot of money for tickets booked close to departure. Let's say I want to fly LHR-HKG, departing on Mon 29th Dec, returning on Sun 4th Jan in CW (booking today).
The current BA.com fare for this itinerary is £6066, booking into D class. This therefore means that seat selection is not free (for non status pax).
The same itinerary on CX is £5115, including free seat selection.
Forgetting the fare difference, how do BA think they'll entice paying CW fares, when they slap on extra fees like this too?
I've no idea how, but all your example illustrates is that this is an effective policy. BA have been doing this for years and somehow their aircraft are never empty on that route. Even if pax are sitting in a seat they only picked 24 hours previously.
I think the final proof is that many corporates with negotiated fares don't stand for this nonsense; seat selection is free on their tickets.
Corporates often negotiate a large free baggage allowance as well. Is that proof that baggage fees are nonsense?