What about the two Club seats 60A/B that have to remain unsold just in case one of you wants to watch a film? Two flights to SIN every night, four Club seats that can't be sold. 730 Club pax denied a seat with a fare of £3500 average each way = £2,555,000 each year lost by BA.
Could say the same about all the cabin crew rest seats on all the flights across the network. Including all the two flight crew sectors.
Careful what you wish for.